I would say that he isn't feeding to sleep but is using the bottle/paci to relax.. I personally don't think it's an issue unless he is waking at the end of each sleep cycle and throughout the night.. if he can transition, he's only using it to relax, not a true prop. Just be mindful of him falling asleep while actually drinking his bottle.
As for the bottles being split - if it works for him better to have two smaller feeds, that is okay. Some are just better with this... that said, it is somewhat like snacking for sure! My only concern though, are you using one bottle with a big feed, offering some, then offering that same bottle later on? Once a baby starts to drink a bottle, it has to be finished within an hour as bacteria from bub's mouth gets into the milk and starts to multiply rather quickly..