It depends on how much attention they get andwhether they're kept indoors or outdoors. Rabbits are verysocial animals. House bunnies are more a part of daily life,and even when you don't have time to let them out and play with themthey can still see people. Outdoor rabbits get lonely muchmore easily and really need to have a lot of time, several hours atleast, spent with them so they don't feel lonely. Withoutdoor rabbits it's more important to have a bonded pair because it'sdifficult to spend that much time outside with them.
But keep in mind that just because rabbits like each other when they'rebabies doesn't mean they'll be okay when they hit puberty.I've seen so many problems with littermates fighting when the hormonesset in. It's much better to adopt a spayed/neutered bondedpair from a shelter or to have the shelter help you bond twospayed/neutered rabbits.
Personally, I love having bonded rabbits. They're so cute when they snuggle together and binky together.