A few minutes clicking on the CASA website got me this:
5.84 Private pilot (aeroplane) licence: aeronautical experience required
(1) For the purposes of paragraph 5.77 (1) (f), a person’s aeronautical experience must consist of at least 40 hours of flight time as a pilot, being flight time that includes:
(a) at least 5 hours of general flight time as pilot in command; and
(b) at least 5 hours of cross‑country flight time as pilot in command; and
(c) at least 2 hours of instrument flight time.
(2) The 40 hours must be recognised flight time that was flown in a registered aeroplane, recognised aeroplane, helicopter, gyroplane, glider, power‑assisted sailplane or group A ultralight.
(3) For the purposes of paragraph (1) (b), the flight time must include 1 flight of at least 150 miles, that includes at least 1 full stop landing at, and at least 1 take‑off from, each of 2 or more aerodromes:
(a) that are not the aerodrome from which the flight commenced; and
(b) that are not within the student pilot area limit of the aerodrome from which the flight commenced.
(4) For the purposes of subregulation (3), a landing is a full stop landing if, after landing, the aeroplane’s speed is reduced to taxi speed before take‑off begins.
Civil Aviation Regulations 1988
I don't see any specific requirement that the "dual" time has to be with an Australian instructor, or that the hours flown has to be on an Australian registered aircraft, or in Australian airspace.
Of course I'm not an Australian Aviation Lawyer, and there may well be a rule somewhere else that limits you to, somehow, training under the Australian ruleset exclusively. But in general this is consistent with what I've found in other countries: As long as you are training for some sort of ICAO PPL, then the hours are essentially transferable towards the experience requirements for another ICAO PPL.
But like I said earlier, make sure all the paperwork is "In Ordnung" and if you really want to make sure the hours are recognized, talk to CASA directly.