We have had this question in CT, as well. It has been fueled by a very confusing letter from the manufacturer to every town's building department.
Our official response has been to ignore it. All gas appliances are bonded by the EGC, and thereby the flexible gas pipe as well. Isolated portions of this gas piping are not likely to be energized, and therefore do not require bonding [250.104(B)].
The NEC does not allow the gas piping to be used as a grounding electrode, so where it comes out of the earth is never bonded anyway [250.52(B)(1)], and the gas code requires an insulating fitting where it comes out of the ground.
What I do not understand is how this pipe is "failing due to lighting". A lightning strike is seeking an earth ground. If the service conductors are bonded properly at the service, then there is no way the lightning could make it into the house along the branch circuit conductors, through the appliance, ignore the equipment grounding connection, and follow the gas pipe back through an insulating fitting at the gas meter. Electricity takes every path presented to it, but in this case there is not a path presented through the gas pipe.
My guess is this piping is so thin it is actually failing due to contaminants in the gas delivered, not lightning strikes.
