Actually, in this case I don't see any liability for the dealership. It's not their fault Harley gets their aluminum parts plated by people who don't know how to properly plate aluminum. This is what happens when bean counting management overrules the engineering folks and gives the contract to the lowest bidder who doesn't meet all the technical and process specifications. The bond of the chrome to the wheel should be many times stronger than the adhesive weight's bond to the chrome plating. Obviously in this case it was not. And odds are if testing was performed on other locations on that same wheel, you would find more plating failures.
Btw, Harley has a history of failures with various chrome plated aluminum parts. It's not just wheels, but also mirrors, footboards, and anything else made of aluminum. They usually try to BS any customers who complain, blaming the pitting or peeling on the environment or where the owner stores his bike or anything they can dream up other than p-poor part quality.
Before I'd pay Harley one red cent toward a new wheel, I'd check with some of the aluminum wheel repair and replating shops. If the wheel is in otherwise good condition, I'd bet you could have it repaired for a third of what Harley wants for a new one. I know there are some guys on this site who have had their wheels replated, since we've had these discussions many times in the past.
Jerry