I have a very similar system to yours. I have an iMac G4 - mine is slower, with an 800MHz CPU and a 100MHz System Bus, but I have a bit more RAM - 768MB, compared with your 512MB.
Tiger runs great on my machine. It's faster than Panther in some respects, and about the same speed in others. It does slow down a little when using a lot of virtual memory. I have a little utility that shows, in the menubar, how big my VM swapfiles are. When VM size gets to 1GB, I see some slowdowns. But again, the slowdowns are no more noticeable than they were in Panther.
In sum, I'd say you're good to go, no problem.
Best,
Matt