First thing I would do is call the breeder you got them from and see if you can take them back. The breeder may not let you, but it is worth the question.
It is very difficult to treat sickness in rabbits. Even if your bunnies do get better, they might always be prone to flare ups whenever they are stressed. Breeding them later on is also risky, because some disease can be passed on genetically in rabbits. Finally, even if they fully recover they might always be carrier of the disease, so it could be risky having them around other rabbits.
( I don't know if you have other bunnies, but if you do you need to quarantine these two immediately!)
I know a lot of people who have struggled with respiratory diseases in their rabbits, and it is often a long, difficult, expensive, and heartbreaking ordeal trying to get them better.
So if you can return them to the breeder that is really the best option. I don't know if you plan to breed, show, or just wanted pets......but starting off with sick rabbits is just setting yourself up for failure.
Good luck. Hopefully it turns out to be a minor issue that is easily resolved, but if not I hope you can return the bunnies and start over.