Originally Posted by FlyingConsultant
I assume "bonded" refers to composite materials.
It doesn't actually. It refers to the (usually flexible) metal strips that
electrically connect moving parts (like controls surfaces and flaps, or doors) and removable parts (think tail cone, for instance) to the main aircraft structure. If those strips are absent or defective, the current from a lightning strike can take highly undesirable paths, such as via actuators or control rods.
As to the behaviour of composite materials during lightning strikes, I have no idea either. I hope somebody else has some answers on this. I would have thought the "bulk" electrical resistance of composite materials would be a lot higher than that of aluminium.