How are these fire places operated?
Where/what is the final gas connection?
What is the final gas termination?
If any of these items are cord and plug connected,then they are bonded thru the EGC.
If they are hard piped into a unit,that is hard wired IE: furnace,boiler etc..They are bonded thru the EGC or the water piping.
I see no need nor does the code making panel for additional bonding.
Good score for no reason. Charge accordingly.
