Our iguana is still pretty tiny (though when I look at pictures of when we first got him and observe him now I'm convinced he's a sneaky growth ninja). We've let him out a couple of times, but due to his greased lightning abilities it's always by himself. Not sure how it's going to work when s/he gets older, I was reading that they aren't the most fond of snakes. At the moment he watches the snakes when they're out and just seems mildly curious, if not indifferent.
Once Bruce is older, we'll see how he reacts to them. The snakes don't care a bit about other animals around (other than rodents) unless they're being touched/bothered. Don't see them caring about the iguana as much as he might care about them, we'll see!