Yes, yes... I forgot to mention that. That's important, but then again, the container he is currently in probably isn't able to really cycle. With only the polished rocks, there's not much surface for bacteria, and doing any bit of a water change would get rid of most of it. If it were me, I would go ahead and move him into a 5 gallon, and do partial daily water changes until it's fully cycled. It's only one fish, and there would probably be less ammonia in a uncycled 5 gallon that in a little bowl (as long as you did daily water changes for a bit).
Using the water from the bowl and the rocks would help. As long as you did that, it really can't be any worse than the bowl. That's all the bacteria there is in the bowl, so using that, and then having several more gallons would definatly be better.
But that's just me.....