Pressure limits of Coopers Ox-Bar PET bottles?

I'm wondering what the upper pressure limits are for the Coopers 500ml Ox-Bar PET bottles. If I want to brew e.g. a wheat beer with a final carbonation around 4.5 volumes CO2, will the PET bottles handle that?

I'm presuming they will, but good to be sure before hand ;-)

They sure will, I carbonated the exact same kit at around that carbonation level. Though you might find that it is a bit heavy on the carbonation; I felt mine were obtrusively so. You shouldn't even carbonate lagers to that level. A wheat beer should be quite smooth in regards to carbonation.

Have you tried adding a teaspoon of bitter orange peel and crushed coriander seeds to that kit? It gives it a taste not far off a Belgian wit.