"Part 61 includes a glider pilot licence (GPL), which is ICAO compliant. To obtain the licence, you must be at least 16 years old.
You are also required to have (amongst other things that apply to all licences, such as aviation English language proficiency and a background security check):
a pilot certificate issued by a recreational aviation organisation that administers glider activities
undertaken at least six hours of flight time, including two hours solo, as well as 20 launches and 20 landings in a glider or motorised glider.
As an ICAO compliant licence, the GPL is expected to be recognised by foreign aviation authorities and this will assist Australian pilots wishing to participate in gliding competitions overseas."
So if you want to fly gliders here, your certificate is sufficient, but if you want to fly them o/s then you can get a CASA licence.
Kaz