I don't know if these guys are old enough to be eating grass. It can be hard on the gut and cause gas. I also worry at this age that he has an overgrowth of bad bacteria in his intestines, as this can be quite common with young bunnies. We need a few questions answered first, though, before we can help.
1) how old are these bunnies?
2) Are they weaned? At what age were they weaned?
3) What is readi grass? What is the dry food? What did the mother eat while she was feeding them?
With babies this young, they can go downhill very quickly. There are some parasites of the GI tract that baby bunnies can get, and if they are weaned improperly, they can get GI bacterial imbalances that can kill them very quickly. The very best thing you can do is take all of these guys and the mom if possible to an emergency vet that is rabbit-savvy. If that's not an option, we can try to help, but I want to assert that the only things that cause bloat in very young bunnies are serious issues that need vet treatment for a successful outcome. If the bunny is older than 6 months, for instance, we can probably help, but younger bunnies have different GI systems.