Another question about IT

Near the end of the book there is a sequence in which Bill is riding Audra on Silver; she suddenly starts speaking and asking questions and it is clearly a special moment in their lives.

But then in something that follows, Bill makes reference to waking from a dream.

My question is this - was the bike ride, conversation with Audra and the special moment the dream he was referencing? Did any of that happen in real Derry time so that there is kind of a happy reunion for those two? Or did he just wishfully dream it as a desired outcome? Or was the referenced dream more about his dreamy remembrances of his times with his old chums, the Losers?

Anybody got any ideas?