Just to let you know that we gave a bottle to our son through the night for a long time as well thinking that he was hungry becasue he drank it - but this was not the case - he became accustomed to it. He would wake up, know that we would come in with the bottle and then go back to sleep after - it was habit. He was not used to getting back to sleep on his own when he woke in the night. Once they are on solid foods and eating somewhat well in the day, they do not need that bottle/or 2 at night.
We cut down on the amount each time and also started to water it down until we were almost at nothing. So if you are at 100ml - cut it down to 80/60/40 every couple nights - and you can add water to water it down. If you do it gradually, he might not notice. When you are at next to nothing - just go into the room, lay him back down, say night night and leave. I don't know if you rock him or does he go so sleep on his own?? With our son, we would lay him down, say still sleepy time and leave, we would then give him time to settle and if he still needed us (crying hard) , we would go back in and do the same thing (wi/wo with pd). This took about 2 weeks but we finally got him down to sleeping from 7pm-5am, wake, bottle then back to bed till 6:30am. We then got rid of the 5am bottle by doing the same thing - watering it down, then nothing. We wanted to move fast, because we were sick of getting up in the night - and I must say we did it for a long time too. So, we decreased the amounts fast and then just stuck to our guns with the put down, walk in/walk out method and now we have not had night wakings for a bottle in months. Our son is now 16months old and sleeps 11 hours straight every night.
I would come up with a plan, stick to it and you will see results. At first it will be hard because he's not getting what he's used to, but after consistently doing the same thing, he will catch on fast.
Good luck