I think they were on the bus because Amber had some drinks too and she didn't want to drive. Or maybe she just doesn't have a car? I don't entirely remember. Or maybe she thought she'd use House's car but then she had few drinks (which I know she did) and didn't drive.

I don't know how bars work here, I'm underage XD

Honestly, it was the saddest thing ever. RSL is love but yeah, they totally made that over dramatic. Why didn't he call her parents? The writers need to get this show back to where it was good. If Wilson and House aren't friends I think I'll die.