I haven't flown in Australia for over 10 years but I downloaded the Australian AIP for a laugh.
ENR 58.4.4 has some guidance.
58.4.4 Alternate Aerodromes - PAL. An aerodrome may be nominated as an alternate aerodrome provided that, where an aircraft is an RPT aircraft (excluding aircraft engaged in cargo-only operations or an aircraft below 3,500KG MTOW), or is an aircraft fitted with single VHF communication, the alternate aerodrome must be one which is:
a. served by a lighting system which is not pilot activated; or
b. served by PAL and there is a responsible person in attendance
to manually switch on the aerodrome lighting.
In the case of a non-RPT aircraft, RPT aircraft engaged in cargo-- only operations, and RPT aircraft below 3500KG MTOW, where the alternate aerodrome is served by PAL, there is no requirement for a responsible person on the ground to be in attendance, but the aircraft must be equipped with:
a. dual VHF; or
b. single VHF and HF communications and carries 30 minutes holding fuel to allow for the alerting of ground staff in the event of a failure of the aircraft’s VHF communication.
So, depending on what operation you come under depends on whether or not PAL is acceptable by itself. From what I can see, PAL is ok so long as you meet the provisos set out above.