I've started giving LO a bottle at night - sometimes expressed milk sometimes formula (if I haven't expressed enough). He's 13 weeks now.
However I've noticed he is fighting/playing around on the breast - which in turn is making him posset up lots of milk. But the bottle he is very calm for and doesn't seem to bring up anything. Could be as the bottle is at night he's just in a calmer frame of mind and less eager to play. But obviously I'm keen to carry on breast feeding the bulk of the time - so any tips on how to get him to feed more calmly during the day. Worried that he isn't getting enough milk to start with then he brings some up so there is even less in there.
A bottle is EASIER to get milk from...less work then the breast...and we all will take the easy route if we can.

I gave both bottle and breast and it lasted 10 months before my son decided bottle was more mobile and easier. Sad for me...but he's content.
I would see if you can get your hands on some preemie nipples or the lowest flow you can find...because the more 'breast like' the bottle is, the better. And the slower flow are going to be some work to get the milk out, similar to the breast.
I would save the one a day bottle for mid-day when you might be pushing a shopping cart as well...lol...and save the calm loving bonding of breastfeeding for the night feeding.
Best of luck!!!