GTW was only a few years old at that stage, and VEW I imagine didn’t have much to spend on programming. Both not big markets.
btw, the TV Week Appreciation Page on Facebook has the week’s programs for WA from 21-27 May 1988 which just happened to be the first week of NEW10 in Perth, which is very interesting.
For some reason (maybe due to reader feedback?), TV Week later swapped over SBS and GWN, so SBS got the page at the back of the listings and GWN was returned to the main Perth listing pages.