Just my 2 cents, but if I see a domestic water pipe entering a building and a fire pipe, I guess that they are bonded together somewhere outside, but I am not sure that they are. So to make a positive bond, I would bond the 2 pipe sytems together again inside of the building where you can see it. Who knows maybe the domestic water could get turned off at the street and/or the connection of the 2 pipe sytems outside of the building might fail.
