I have hamsters and a bunny. And never the twain shall meet. No one cares (well, Max cares because he steals bedding out of George's outside litter box when it's clean to make a nest in the closet with). I keep the hamsters in their cages while George is out and George's cage is off the floor and unscalable (and man, can hamsters scale things) so she's safe when the hamsters are loose. George could care less about the hamster cages scattered around the room. I think she chinned one. Once. And let me rephrase here: George could care less about the girls because she ignores them entirely but she has peed on Max's cage cover before. The two of them have... issues. Otherwise it's an ignore/ignore situation. At the beginning though, when I wasn't as diligent as I've gotten we had an incident where I thought my little boy hamster (that's Max) was in his cage but he'd escaped. I put Georgie back in her cage which was sitting on the floor and while her back was turned and she was distracted with treats, he came out from behind her hutch like a TV of the week knife murderer that had been hiding in the closet waiting for the occupant to come home. Needless to say I grabbed him before George even noticed but - no. Hamsters and rabbits physically together are a bad idea. As mentioned above, one nip could set anything off and the bunny's teeth are a heck of a lot larger than the hamster's. Not to mention even if they get along wonderfully somehow, one rabbit kick while bunny is jumping off or hopping away and hamster could end up broken. I've heard it happen with guinea pigs and hamsters are so much smaller.
I understand what you're saying about the bunny being lonely while you're gone but - rabbits (at least generally) tend to spend a lot of the day sleeping anyway. There are plenty of bunnies that live happy solitary lives, enjoying having a human to pal around with without any other animals. It's easy for us to think 'well, I'd feel this way' but we're not rabbits and they don't think of things the same way we do. Not saying don't eventually get another rabbit if that's what you want and it works for you, and not saying your bunny might not be delighted with a companion if one arrived. Just that you may be feeling bad about something your bunny doesn't even care about or notice.