This all seems rather confusing, but I'm not sure how much I can believe and agree with viniferum being a separate species since it was never again found as a population.
At least now I know what they mean when they say viniferum.
but isn't there a term for a vine colored callosum then?
Well, the Kew World Checklist doesn't make things easier as they reckon, that P. viniferum is a synonym of P. callosum var. viniferum (recte: fma. viniferum)?!
According to Sam's description, Perfect Circle is a "regular" variety of callosum ( I take it as peacock or coloratum) and vini beauty is as the name suggests, a dark color form. Now, I don't know the details on that latter one.