Coming in late, but my twins were born 2 months early (31w+1d to be exact), stayed in the NICU for exactly 4 weeks and aside from the usual issues from being born early, like some early bradycardia while feeding, reflux, being sleepy, and slow to nurse well... they were and are totally fine. Within a few days, they left the critical care room and were put in with the other "feeder-growers" in the adjoining NICU room.
Reading these posts, I think (being honest!) you need to stop worrying about bottles.
Full term baby, sure, but not 32 weekers. Right now, the important thing is get these babies growing and second only to that is get them HOME. If you have to show they can take 8 bottles a day then so be it. That sounds pretty standard to me and my twins were lucky enough to be at one of the best NICUs in the country. Believe me they are far better off at home then they are there, bottles of EBM or not. Also, I don't know of any babies born that early who don't do things backwards - out of necessity - for example, the first thing in my dd and ds' mouth was an NG tube, followed by a pacifier (which believe it or not is a GREAT thing, so they learn to associate sucking with feeling full), followed by a bottle, and last came my breast when they were 1 week old. The best thing I did was pump my brains out
(at least twice between 1am and 5am, plus at least 6 other times during the day using a veeeery powerful double electric pump... Medela Lactina to be exact). This ensured dd and ds were only getting my milk, which is far and away the most important thing, especially for preemies (my milk was so creamy and rich -- preemie milk is truly unbelievable!
Many babies, preemies especially, don't develop good nursing reflexes until they are much closer to their original due date, even 1-2 weeks beyond. Mine were weak and clumsy nursers until they passed their due date then all of a sudden they "got it".
I was in the NICU from morning until night, and when they closed for 1 hour during the day for rounds, I was pumping and resting in the mother's room nearby. I was bound and determined to breastfeed -- EVENTUALLY -- but knew that the fact that they were exclusively breastmilk-fed was paramount to all.
So anyway, yes, they got bottles in the NICU. Lots of them. We worked on nursing as much as we could, but frequently they would need to be supplemented (with my milk) or skip a nursing because they were too tired and be tube-fed instead. Once they hit 35 weeks they were able to take a full day's feeding by mouth (mostly bottles, 1-2 nursing sessions each), and they came home.
From that point, I worked daily with an LC who specializes in preemies. She came to my house and helped me eventually ditch the bottles in favor of finger-feeding, Medela SNS, and just nursing. By the time they were 1-2 weeks past my original due date, they were nursing exclusively.
The best book I ever read was Mothering Multiples (by Karen Gromada) - it's the La Leche League book for nursing (and parenting in general actually) twins.
I hope those babies are healthy and thriving, and get to come home soon.