We were on 3 bottles by 9 months and the main reason was to get my DD to take more at a feed and it did work. We did a wake up feed, a snack mid morning then a bottle after her lunch just before her pm nap. Then she had her third bottle at bedtime, with a small snack after nap if needed and her evening solids around 4.30/5pm. I got 20oz+ a day in her that way, on more bottles she was taking less.
What are you doing with the night bottle? We dropped it by decreasing the bottle by 1oz every 3 nights and then when it got down to 2oz we just offered water and resettled. It worked well as she got used to less milk gradually.
Laura