Adelaide Vegans is easily the biggest and most active vegan community group in Adelaide.
Their website is fairly extensive offering a forum as well as information on vegan business and other vegan specific information. It is free to join for vegans and those aiming to become such.
They run events which are mainly dinners on Friday nights at a select number of restaurants. Details are on the website.
So far the people have been pleasant enough and the loosely associated Facebook page seems to keep vitriol under control while remaining acceptably active.
I have not found much information on structures, rules and the leaders.
I am a member.