like anything in the world of clubs......there are no hard and fast rules that can you strictly apply in every case. much of the criteria depend on how the bouncer is feeling at that particular moment, how busy the VIP is, what first impression you give off.
amnesia do roll out the "only trousers and shoes" policy for the VIP but i've regularly been in wearing 3/4s and flip flops.
if you get a chance to access amnesia's VIP, then do it cos it the most spectacular on the island and not just like being part of the same room except behind a rope.....like pacha or space.