Hi NewMommy,
I wouldn't worry, he's still so little! 1l milk per day is considered the "maximum" if baby is also eating solids, and he's still far from that.
My LO dropped each of her bottles when she was ready, at 12 months she only had the morning and evening bottles left. I never consciously took any of her milk feeds away, she just started pushing it away and refusing to have it. I'd keep trying every day for about 10 days, and then I'd stop offering.
Every child is different, some are completely weaned off the bottle by 12 months. Unless your paediatrician has concern about excessive weight gain, I wouldn't worry about it.