The whole ULCC and LCC model is basically unviable with oil above $100. These words came from an ex Irish loco boss that I once worked for.
The others have loyalty programs, contracts, corps, and the ability to hike prices to play it out.
Rex and Bonz will lose an absolute ****load if Fuel sat at such prices for the next year or two. More likely than not it seems. Especially in that they are only charging airport costs to fill the machine, let alone paying for fuel.