I would add more solids, 34oz is a good amount but you don't need to decrease it at all when he gets to 6 months. Milk needs to be more important than solids until 1, so you should find that his solids increases gradually as he grows. When he gets to 9/10 months you can drop to 3 bottles and then down to 2 bottles around a year.
For now then increase his solids a bit and gradually work up to 3 meals, you can make his bottles 9oz as well, but don't reduce the amount of milk for a few more months yet! If you find his milk intake reducing as solids increase go slowly or even reduce a bit to keep his milk intake around the 30oz mark at least.
HTH!
Laura