Hi Delia,
SA stands for Separation Anxiety.
I can't see any problems with your routine, it looks good. Like you said it could become a problem that he's falling asleep with the bottle, but as long as you don't give him a bottle at night when he wakes he won't get into a bad habit of waking for one. Maybe try getting him to finish his bottle before he goes in his bed though, so he gets more chance of settling himself to sleep, it is well worth it to make toddler sleep better later on too.
When he calls you you can try just responding with voice, telling him you are right there but that it's night time and he needs to go back to sleep. If that doesn't work after a while go in and tuck him in, telling him the same things to reassure. If it's SA related it will pass as he grows, and the best thing to do is be gently reassuring but without geting onto AP habits if you can help it. He'll eventually get used to the fact you are there for him if he needs you and won't bother calling you if he goes in to a light sleep or wakes in the night, and just go back to sleep on his own.
Most kids go through a period like this though, and it will pass.