Most bottle fed babies drop to 3 bottles around 10 months. Milk needs to be the main source of food until they are 1, so you don't want milk intake to start dropping too soon.
The usual pattern is around 10 months to move to a wake up bottle, a post lunch, pre nap bottle and a bedtime bottle. They tend to drop to a morning and bedtime bottle around 1.
Your current routine looks great, I would introduce finger foods with the meals you have rather than rushing to introduce another meal. You don't want milk intake to drop below 24oz, so if he starts refusing milk then you will need to scale solids back until the milk intake picks up again.
HTH!
Laura
