[ricksplat]

If you take for instance "Champagne" - you might have an equivalent product but it's not "Champagne" unless it comes from the Champagne region of France. Yet alternative sparkling whites such as "Prosecco" (Italy), "Cava" (Spain) and "Cristal" (US) seem to do quite well. If you have a good enough product, you shouldn't have any need to claim equivalence with another regional variety.

[cromulent]

True. I think that Cristal is champagne though, at least the one I know of. Is there a local Cristal in the US?