There is still a practical R/T exam and I recall doing mine in a simulator (which looked like a booth for a translator at the UN!). This is done at PPL level, and then... that's it!
I got an R/T licence issued with the PPL, with a "VHF only" mention. Then I undertook the VFR and IFR comms exams for the ATPL, and... ta da! my (commercial) R/T licence now mentions "no restrictions", which means I can do HF as well (even though I only know HF theory).
That's about it. All the rest, as you say, is picked up when actually flying (which is why some GA pilots don't get enough exposure to a busy, commercial, R/T environment. I guess it must be frustrating to deal with an unsure GA pilot asking for Flight Information Service in the middle of your airline traffic). I see that R/T standards are taken very seriously by NATS; I think there should be something similar for aircrew; maybe training captains/TREs should simply make a point of insisting on correct R/T phraseology during OPCs/check rides.
Cheers
