The way I interpreted it was that you need to be a member for active support home and away. Given the away bay is for active support you will need to be a member to get tickets to that area.
I hope I'm wrong and not that it will matter to me much but my missus is coming to the Melbourne game and she's tossing up weather to renew her membership this year, not to mention the various Novacastrians that live in Melbourne that will want to sit in the away area.

I think you might be surprised being Villa's first game in Melbourne I think it will go close to selling out, think back 2 years ago for ADP V Heskey first game hyped up.