I have asked Virgin this question before, but I was enquiring about Perth - London or Dublin. They said it would be Economy from Perth - Sydney, Premium Economy from Sydney - Abu Dhabi and then Economy from Abu Dhabi onwards with Etihad.
It's a bit of a crock really unless Virgin fly VA metal to your final destination.
Makes me wonder if one of the 2012 enhancements for VA is the introduction of F. This would put it in line with EY, NZ and likely contenders for their Asian alliance partner(s).
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