It really is hard to say for sure because though some bunnies really are queenish/kingish about the hierarchy, others are much more lenient about it and will groom a submissive bunny once the hierarchy has been set. For example. Bailey and Jack are rebinding right now. Jack clearly displays dominant behavior when first setting the rules, and Bailey is VERY submissive to Jack when they meet. But once they start cuddling, he will groom her and vice versa.
Jack does not lick/groom me, I pet him only. But he never shows dominant behavior toward me
Rucy does show dominance but will try to lick me, but I can tell she’s not liking the taste of skin or cotton. She ends up grooming the floor right next to me. Bailey is also a dominant female and will insist I pet her, but she will sometimes lick my clothes after a long petting session.
I just think that once the hierarchy has been set, grooming no longer has to be a sign of dominant or submissive behavior with many bunnies. It can just be sign of friendship even if they don’t groom back.