There's no bulk get operation in Hot Rod, but the Java Hot Rod client has implemented via RemoteCache the getAsync() operation, which returns a org.infinispan.util.concurrent.NotifyingFuture (extends java.util.concurrent.Future).
So, if you want to retrieve multiple keys in parallel, just call multiple times getAsync() and when you need the values, just call Future.get(), or attach a FutureListener to the NotifyingFuture to get notified when the value is ready.