@butterfly, in my case I put the ANZSCO code ng TRA, I think they will understand why you need the PTA pag nalaman nila na TRA ang assessing body mo.
Kung e- accredit nila or not, sila nalang talaga ang makapagsasabi, wala naman silang hininging docs bout sa employment mo. Just provide the docs according dun sa list nila, and fill the questionares, I believe it will be fine. Upload PRC docs (Certificate, result, etc), may binanggit dun sa website na it will be at your advantage kung isama mo yon.
To ease your worry bout link to job and degree, I have 2 BS degree, isang engineering at isang pure science, I submitted documents for both and both were evaluated as AQF degree. Yong pure science ay di related sa ANZSCO ko.
God bless your application. Go ahead claim it, it should be fine.