I just read a list of symptoms and types of ear mites in rabbits on petmd.com, and it does mention hair loss and peeling of the skin around the ears, which your bunny has, but since you aren’t seeing any other symptoms, it seems like the vet needs to make a definitive diagnosis of ear mites, ruling out any other conditions, before proceeding with treatment.
Here is the list I found at https://www.petmd.com/rabbit/conditions/ears/c_rb_ear_mites
Mild to moderate itching around the ear, head, and neck
Intense itching (more common) primarily located around the ears, head, and neck; occasionally generalized
Head shaking and scratching
Affected areas may become extremely painful
Thick, brown to beige crusty exudate in the ear canal
Occasionally, brown to beige crusting and itching occur on the ears and feet only
Hair loss and peeling of skin around the ears
Signs of ear infection may also occur
Mites and lesions may extend to the face, neck, abdomen, perineal region, and even feet via grooming
The vet who treats the rabbits at the sanctuary where I volunteer gives injections of Ivermectin for ear mites. I believe the rabbit gets 3 injections, one a week for 3 weeks.
I hope your bunny’s ear condition will clear up soon.