The gas line is bonded to the grounding electrode and the CSST is bonded to the rigid gas line. Bonding and grounding are different.
CSST manufacturers have specific bonding requirements which, in some cases, include installation of additional grounding electrodes. The requirements vary depending on the Lightning Density Zone (LDZ) of your area.
I am in the process of doing research for this topic. Just to let you know that CSST is not UL listed, it is CSA listed. CSST was originally trying to get a UL listing and they did not pass the evaluation there.
The change in the manufacturers installation instructions which happened just recently has some discrepcencies.
did they go back to the listing company to get the new instructions evaluated by the listing company…
There are discrepcencies with the method they provide for bonding the system.
most problems they have encountered are due to lightning/grounding issues not bonding issues. This system is not permitted to be grounded
I could go on, but I will wait until I have received more info back.
As a HI, I would defer all discussions or recommendations back to the building department or AHJ and pass on that responsibility/liability.