None taken. The NEC does not spell out where the water bond has to be, It only spells out that it has to be a water contact area of at least 9 square inches. I will agree that some systems that have bypass loops in place for heaters could circumvent the bond and that would have to be taken into consideration when designing the bond system.There are a few devices out on the market that are designed to be a water bond. One good one is mounted in the skimmer and sits tight against the wall. Another one replaces a hose connection at the pump or skimmer with a stainless steel fitting that can be bonded to. Resistance of the water is not realy an issue in this situation as the bond is meant to equalize potential difference by eliminating resistance between two different potentials. Without the bond in place you become the resistive path between the potentials and it can sometimes be painfull. Here is an incredible video of how voltage potential works. http://www.youtube.com/watch?v=LIjC7DjoVe8 At 1:38 in the video he somewhat explains how potential works.
Remember, in a grounding system, we are flowing current from the defect in the electrical system back to source. The ground wire acts as a low resistance path so you don't get shocked. In a bonding system we are simply keeping two or more voltage potentials equal. As long as the bond between these different potentials is of low enough resistance they will equal out and you don't become the conductor
Resistance = impedance for AC right?
Can pool water be bonded within the plumbing only? Luckily this is one of the few problems I've never experienced with my 40(?) year old pool.