AltFlaps, I believe Amsterdam stating the TA/TL on the ATIS is a byproduct of their low published TA of 3000'. I think they have to adjust actual TA any time the altimeter is below 1013 in order to maintain obstacle clearance. However, I stand to be enlightened by anyone with a better understanding.
Aerocat, you are correct. Transition layer is not particular to Aus/NZ, it just hasn't been discussed yet.
US airspace does not utilize the TA/TL nomenclature. If we did then TA would be 17000' and TL would be FL180 or FL190 depending on local altimeter.
Best,
GC