The traditional explanation for Philip's failure to share the Holy Spirit in Samaria is that only Apostles could do that sort of thing. What I see, instead, is a clear implication that Philip didn't know that Samaritans were sons of Abraham whose men were all circumcised. This subtext becomes more explicit immediately thereafter when Philip encounters the eunuch and - again - baptizes him in water but does not provide the Holy Spirit. Just like the poor gentile widows whom Peter would not eat with, this poor eunuch was unable to fully convert. But although Philip had disappeared from Acts after that episode, he now reappears in this church which began with Cornelius. This suggests Philip has also changed his mind about circumcision and the Spirit.
It's significant in Acts 21 that Luke meets Philip in Caesarea.
After Luke leaves Caesarea when Paul leaves, Luke presumably returns to Caesarea after Paul returns - certainly some time before chapter, when the "we" narration picks up again. Therefore - within the world of the narrative - Luke stays in Caesarea for up to two years. Given this point, and remebering how much information Luke has already shared about Philip and Cornelius, there should be no doubt that Acts wants us now to suppose that its narrator learned about Philip and Cornelius by spending much of these two years in Caesarea.
Please note, the point here is strictly literary. This applies equally whether you take Acts to be fictional or non-fictional. Either way, the character who is narrating has just met Philip and spent time in Cornelius' church. We don't have to take this as history. We have to take this as realism. We have to take this as if it were history... because if this is fiction, it's very sophisticated fiction, and that's the kind of reading sophisticated literature demands. (F.R. Ankersmit: "We read the novel as if it were true, and the failure to do so will make nonsense of the literary text.")
Fact or fiction, this is how Acts works, as literature. Ostensibly, Luke's two years in Caesarea provides a narrative explanation as to how and where this narrator learned certain characters' stories. More importantly, this binds Luke's perspective on their stories to these Caesareans' perspectives about their own stories. When Luke narrates the story of Peter and Cornelius, we ostensibly get Cornelius' slant on that story. When Luke narrates the stories about Peter and Philip, we ostensibly get Philip's perspective as a member of the Caesarean church. Ostensibly, there's a reason why Luke picked up and passed on those stories about these people, whom he now settles down for as much as two years. The Caesarean perspective puts a heavily critical spin on Luke's stories about hungry gentile widows, the samaritans, and the eunuch, and the hungry gentile widows.
As a character in the story world, the narrator's perspective identifies with the Caesarean perspective.
This makes us read the stories about Philip as critiques against Peter's early position on circumcision, intended to illustrate that Peter's initial bigotry against Cornelius was neither a rare nor an isolated event. This stretches out Luke's critique, which continues in Acts 15 when "certain ones from Judea" demand circumcision in Antioch, and when Peter stands up to argue against the christian Pharisees in Jerusalem who were still arguing the point at the council of Jerusalem. Note this carefully. The fact that Luke has Peter arguing against these Pharisees is a compliment to Peter. The fact that it's been many years since the Cornelius incident and Peter hasn't already convinced everyone in Jerusalem is a critique against Peter. It's also a critique against the entire church in Jerusalem.
In Acts 21:12, after Agabus' warning, the Caesarean church urges Paul to avoid Jerusalem. By itself, that urging can be seen strictly as a response to Agabus. However, in the context of all I've just said, Caesarea's urging to avoid Jerusalem cannot be taken as an isolated element of Luke's narrative, and especially not given what follows. When James mentions "many thousands" of Jerusalem christians, in 21:20, he goes on to describe people who are not willing to welcome Paul as a brother unless he can prove he keeps the law in precisely the ways they expect him to keep it. Putting this description on James' lips is a condemnation from Luke. This condemnation harkens back to the warning of 21:12. The Caesarean's urging was not about Agabus prophecy. The Caesareans knew what these Jerusalem christians were like. They'd had first hand experience, dating as far back as Philip's first hand participation in the dinner-time bigotry against unconvertable widows. And since Peter (apparently) left, the culture had only gotten worse.
Acts 21 is the place we must start if we want to understand how Acts works as literature because it shows us that Luke shares Caesarea's perspective on the church in Jerusalem, and that identification colors everything else that takes place in Acts (that doesn't center on Paul).
By the way, I do not personally see Luke's critique as anti-Jewish or anti-Judean. Because Luke liked most Jews, it seems, we must conclude that Luke's critique is anti-institutional, or anti-authoritarian. We see this most clearly in Stephen's speech. Unforunately, connecting that argument with today's argument would require a whole different discussion.