You would definitely have to have him neutered before you attempted bonding. That is always the first step to bonding – that both rabbits have to be spayed or neutered. If he is a year old and not neutered, you should be able to see his testicles. They look somewhat like pink lima beans. He is well past the age where they would have shown up. Rabbits can sometimes suck them up if they are frightened or nervous, but that usually happens at a vet’s office or some place that would cause nervousness, not normally in your home. If you do not see testicles, than he is either neutered or he may be a female. I see that your friend got him from a pet shop, so if she never had him neutered then he almost certainly isn’t. That’s not something that pet stores do. Although, pet stores sometimes have rabbits from rescues that are up for adoption, and those would probably be spayed or neutered. Pet store workers know very little about rabbits and frequently tell people the wrong gender. That is why people who get two rabbits that they thought were the same sex, often end up with unexpected litters.
If you are at all contemplating getting a companion for the bunny, even if it’s some time in the future, it might be good to go ahead and have him neutered now. You may want to make sure of the gender first.