Welcome to RO, it's a great place to meet and chat with other bunny folks.
For my rabbits I have two pair. Rebecca and Ghirardelli are bonded then Cinderella and Houdini are bonded. All four of them play together with supervision. However, if food is involved in particular, Cinderella gets nippy with Rebecca to the point that Rebecca was getting very thin when they were living together.
Ghirardelli will groom Houdini so I would consider them friends, but not bonded because they do notlive together. I think there is more of a protectiveness when a pair is bonded. If I am doing something with one of the pair the other is always watching. The pairs are seldom very far away from each other even when they are running all over the house. I think it is the safety they feel together than strengthens the bond and makes it dangerous to separate them.
Whenever I take one to the vet they both come. When we go for a walk in the park in the stroller, they all come. Off to the pet store, they all go. You don't want to bring one home with a strange smell because smells are so important for rabbits to recognise each other since in the wild they would be in dark burrows a good deal.
:twocents