I'm in the same situation. I love the night time routine of rocking and giving a bottle to him. But I know the bottle has to go sometime. I'm thinking this summer (once i'm done teaching) I'll start giving him less and less until he doesn't need it anymore.
DS pretty much let us know when he didn't need it anymore. He started only taking an ounce or two of it. I guess he was drinking so much milk throughout the day and eating enough at meals that he just didn't need anything else at bedtime. So we just stopped it a couple weeks ago, and he hasn't even missed it! Now one is completely off bottles just in time for #2 to make his arrival next week )
We got rid of the bottle at 12 months. We do offer him a sippy of milk about 30 minutes before bedtime just to "hold him over". We then brush his teeth to get the milk out of his mouth before going to bed.
Around 14-15 months old we stopped bottles with my DD. We replaced it with a sippy of milk and a story with daddy. Sometimes she drinks more milk than other nights, but it's usually only a few ounces. We're okay with it for now and feel like she will eventually outgrow it all together.
Re: When to stop giving milk at bedtime?