I am currently in Australia, and have flown between MEL and ADL two times this week. I used my Diamond card for Virgin Lounge access on Domestic DJ tickets on each visit to each respective airport. I am travelling with a Platinum, and there was some confusion by the Virgin staff in MEL as to whose membership had a higher value. They joked with us that I would have to be my travelling companion's guest, and vice versa, but let us in the lounge with no drama.