Baby eating more than 8oz

My baby is 11 weeks old and is eating anywhere from 8.5oz to 9.5oz each feeding. I burp him once during his fed and he doesn’t get fussy or anything but once his normal 8oz bottle is gone, he gets fussy and starts rooting. Then he’ll eat another .5oz to 1.5oz from a new bottle and then is content. Right now it’s like clock work, he eats every 3 hours on the dot. Do I just continue to make multiple bottles per feeding, or is it time to start introducing rice cereal? I’m a FTM so any advice is appreciated!