start all over again, make sure everything is clean, and then clean it again. wash it with wax and grease remover and start again?

Yeah i was affraid of that, i thought someone might have a trick to fix it.

Inclusion of air bubbles in body filler usually means the filler has been poorly mixed, and/or poorly applied to the car. Ie air has become trapped in the filler when mixing the filler and the hardener. A few days or weeks later the trapped air can shrink or expand depending on hot cold etc.

Best to use a wide flat scraper on a large flat clean piece of sheet metal and use wide flat motions to mix taking care not to trap air in the mix. Mix until the filler is of uniform colour. Obviously also be careful when applying to the car. When you get the knack of his process it takes only a few seconds to completely and reliably achieve 100% mix.

thanks for all your help, i will have a few goes to til again to fix it. otherwise i will sell the bonnet and buy another one and weld a steel bulge on. Or possible take it to a panel shop. what ever happens the bugle will be on my escort.