"Can Jetstar survive without QANTAS ?"
Ask yourself, can an aircraft fly without without fuel ?
Considering that QANTAS is paying the Jetstar fuel bill, I would say that Jetstar won't survive without QANTAS.
Any idea that AJ will sell Jetstar to keep QANTAS going is a fallacy, Jetstar cannot survive in its current form without a mothership to provide the essentials.