I think that he is doing just fine. My DD is 9 months and she pigs out in the morning, but now that she is getting solids if she needs a bottle it is really only around 4 ozs, maybe 6 if she is really hungry, especially since she gets solids now. When she was around your baby's age she'd only drink about a 3 oz bottle when she took one, and I'd normally only feed her every 3 hours, plus she was sleeping through the night already too. Now she definitely needs more milk each time but she is also getting more solids too and needs milk less often, so she is still really eating about the same amount of milk now as she did 6 months ago.

I think a big part of the reason that she didn't need as much as often is because I had really fatty milk. I don't pump as much now and didn't really have a reason too, but when I did and the milk would thaw out it was literally 1 oz of cream for every 3 oz of milk. Now my milk is a lot thinner, but this won't start to happen until your baby is starting solids.