Regarding bonding – it will have less to do with their age difference (just 2 years) then it will have to do with whether or not they are both dominant. It depends on the personalities but the good thing is usually male and female bonds are the easiest, but you should still go through the bonding steps.
Regarding the band vs the collar. I know many of us here have not ever had to use either, but my understanding is that if you vet recommends one, or you find that she is pulling out her stitches, then the collar is better because rabbits can still try to chew up the band.
Out of curiosity, how come you can’t bring her inside to become a House Bunny? Is your male a House Bunny? or is he outside too.
EDITED: I forgot to add. Recovery takes 3 – 5 days for her to start to feel better, (though she should start to nibble on something by the next morning after surgery) but you should wait a month though before bonding, just to let her fully heal and let her hormones settle.
Ask your vet about offering pain meds too for the first day or so to keep her comfortable and eating.
This is a great link from the house rabbit society about what to expect pre and post surgery http://www.rabbit.org/faq/sections/…-post-care