A full list of Aerocare's partners are available on the website.
They handle Virgin at about a dozen ports around the country.
In SYD, at the moment it is just Pacific Blue (Virgin's international partner)
There was a contract with UA/AC but that has just this week expired (hence they are hiring thier own CSA's.)
I believe several other carrier's are also in discussion - or so i have been told., and at least one of these is a definate.
There is also some charter work every now and then.
Every other airline besides UA, MH and QF are either handled by Menzies or Qantas.