JMHO,
I fed Coastal Bermuda hay when I lived in Florida, [I also fed perennial Peanut] it was just fine. as mentioned above-- it must be good hay, and smell like good hay, - if it is discolored, or "dusty" when pulled apart it is not good... I liked "Coastal" because of the price, it could be used in nest boxes, as well in the hay mangers. As long as I was not changing the pellet the rabbits were eating at the same time I was changing the hay-- I had no rabbit problems from changing the type of grass hay they were fed. --[ if changing from feeding grass hay to alfalfa, or Perennial Peanut, I would make the change gradually].
[ This comment is based on the assumption that you are feeding pellets as the primary feed, and the hay as an add-on feed.]