I can add a bit of information here, and while this has mainly been obtained by scanning in the Goulburn area, some of it would apply elsewhere in NSW.
ARTC track workers here use either the digital GRN (talk group ID's 11376, 11377) or analogue simplex radio on 450.2125 MHz. It would take me too long to explain how to set up a digital scanner to monitor the GRN, but as advised above, search for your local GRN frequencies via the ACMA database. These will be listed as belonging to the Department of Finance and Services, and are usually between 415 and 425 MHz.
CFCLA here use 450.425 MHz simplex analogue radio as their shunting frequency for the local workshops, now known as the Australian Horsepower Service Centre (AHSC).
There is also occasional general shunting-related talk on 418.800 MHz analogue, mostly (I think) PN workers shunting in the yard.
WB radio is still used here quite a bit, and trains often still call each other complete upon passing. Junee control used to be active in Goulburn on WB to talk to drivers, but now they hardly ever (if at all) respond to requests by drivers on this frequency. I can only assume that drivers, and other workers, now have to call Junee either by mobile phone or ICE/CountryNet radio, depending on which radio is fitted to the locomotive in question.