Qantas and JetStar Symbiotic ?
Jetstar was setup to deal with Virgin in the domestic arena.It has been successful in stopping the Virgin march.
It has not however been successful in the international arena.It has threes faces and no direction.
Qantas survival does not rely on Jetstar.Jetstar's survival relies on Qantas.
From TG's reasoning any major carrier that does not have a low carrier version in its stable is doomed to failure.Thats a stretch.
The relationship between LCCs and their mainline parent is generally parasitic.The LCC relying on the parent for everything from a Res system to maintenance.
It will be interesting to see where these relationships go