Haven't booked with Virgin recently?
It's been per person per booking for a decent amount of time now.
As for the cost separation into GST and what not, not sure I ever noticed it, although I do note that Virgin to tend to separate out the GST from their cost breakdowns (e.g. check the taxes etc. next time - one of the components is GST). So they could very well do the same when itemising out the credit card surcharge, but as long as the net result is the same, I guess no big deal......
If you view VA's schedule of fees, they don't actually state that the prices are inclusive of GST (or what not). However, I assume that by federal law, it's not necessary to state it so, but it is necessary to quote the figure inclusive of GST.