Answer:
Wry neck in rabbits (also known as head tilt, wryneck, and torticollis) can be caused by many different factors. The condition could be permanent, or it could be temporary and curable with medicine, like antibiotics (it could just be an inner ear infection; but permanent damage can result if not treated promptly). How the problem is treated depends entirely on the cause: a special "rabbit-savvy" vet is the one to find the cause and best treatment. Please see the related questions/links below for more info.
Notes from a breeder: One rabbit with wry neck I saved had 2 babies in her litter that also got it and so I think it is best to cull rabbit from your herd. The rabbit will eventually starve to death because it can not eat or drink. It is much more merciful to put it down than to watch it flip in circles and be unable to reach the water dish.