For bonding rabbits, I've only gone through a rescue where I bring my single rabbit in to a rescue to meet other potential mates. I think it can help weed out the "this bond isn't going to happen" rabbits. The bunny date method is really just a way to pre-screen for potential compatibles.
That said, it's not a guarantee, but is less risky (imo) than buying a rabbit and hoping for the best. Unlike Aki, I have had a few bonds that absolutely would not take. (I've also had ones that were easy.) One has to experience the fur-flying, end over end, vicious attack-mode, with-no-end-in-sight fighting, to appreciate just how stressful bonding can be.
In my case, it wasn't my current rabbit that behaved differently at the rescue, but the potential mate. He seemed great with my girl at the rescue but turned vicious at our house. It was no holds barred. We exchanged him for a different boy who bonded with my girl the next day.
On another occasion with a different female, she rejected lots of rabbits at the rescue. As for the rabbits we thought showed potential for her and actually brought home, she rejected two before finally accepting the third. (spaced out over time of course).
If I had not gone through a rabbit rescue, each of those failed bonds would've meant having to house the rabbits separately. That was something I didn't want to risk. For me, it isn't worth it to buy a potential rabbit and just hope like heck that they eventually bond.
I don't know if a rescue would allow you to bring a rabbit home to your rabbit (and not bring your rabbit in to them). That might be ideal for the rabbit owner but not so much for the rescue. It's not the norm for rescues but you never know.