ALA - Aerodrome that complies with the ALA guidelines for dimensions and splays in accordance with CASA's ALA CAAP.
Unlicenced Aerodrome - is an aerodrome other than a Licenced Aerodrome. This is in simple terms a piece of dirt, that is not licenced.
Anything can be an Unlicenced Aerodrome, if it is used by aircraft, but to be an ALA is needs to comply with the CAAP.
Have a nice day.