"Wonderwall" is about Shinji Ikari and Kaworu Nagisa and Noel Gallagher can see into the future.
Noel has said the song is pretty literal in its meaning, being about "an imaginary friend who's gonna come and save you from yourself". Kaworu, when he shows up in the show, is the first person who actually shows any affection for Shinji completely unconditionally, and it severally helps his mental state and makes him feel a lot better. Not only that, but, since he's an Angel in disguise who was sent to spy on NERV, that makes him an imaginary friend is a less literal sense. Rather than being a friend who was made up, it was instead more of a fake friend that turned into a real one.
As for seeing into the future, Kaworu's debut episode "The Final Messenger" first aired in Japan on March 13 1996. "Wonderwall" was written sometime in May of 1995. You do the math.
