B.W.
If your son is teething, this isn't a big surprise. If you don't want to get him in the habit of eating "food" in the night, try putting some cold water in a bottle -- that'll help sooth his gums, without adding a feeding. But if he doesn't like that, I wouldn't worry about it. Let him enjoy his bottle, and once he's done teething, he'll probably go back to sleeping through the night anyway.