best solution would be to heat the strip of mesh up and to melt it into the bumper from behind without going too far to go right thru the bumper, this is when the Power Tec Hot Staples would be ideal as they do exactly this but you turn them once they are under the surface and lock into place so to speak then you should utilise a Flexible Parts Resin on the back of the bumper to finish of the rear repair. I would personley then use a plastic welding gun to increase the strength if the repair at the front. Smooth off with a skim of plastic filler to make it pleasant to the eye, prime and paint. May sound tedious but once you have the idea sussed this is truely the best route to enable the bumper to support what you are trying to achieve without getting cracks in the future.
