Every Wrangler since 1995 has had a galvanized steel body.
If I'm not mistaken, virtually every vehicle sold in the U.S. (if not the world) today has a galvanized body. I certainly haven't seen it even listed on a features sheet since 1998, so I'd have to think so. I do know that the JK is.
As for rust, if you're concerned, a bit of extra undercoating is never a bad idea. I run the el cheapo spray-can stuff, and I've never had a problem.
The other concern is rusted hardware. Anytime you get underneath to remove something, hit it with a shot of PB Blaster an hour before you start to help with that. Otherwise, rock and roll
Whereabouts are you, then? Mark W.