I have no problem with Bautista's bat flip, although had it been against the Red Sox, I would not be happy with it.
That said, Bautista has to know that if he's going to show up a pitcher like that, he should expect to take a fastball to the buttocks the next time the two meet. I have no problem with that either. I like the idea of players policing themselves, as long as it's done correctly and no one goes head hunting.
That said, if the pitcher doesn't like someone showing him up, perhaps he should make a better pitch.