Hi: Sharing is what makes this site fun! 😀
The ground wire should be #6 solid copper, and tied directly into the main panel. (That’s my understanding of code.) That way we know there is only a single ground rod, not multiple rods. This matters because you can develop current between ground rods, unless they also are connected together.
Where you connect the ground/bond wires is affected by electrical breaks in the plumbing. For example, flex connectors may have a dielectric built into their ends, so it would make no sense to ground to a flex line. You might need to ground hot and cold together (above the flex connectors) and bring another ground from the tank itself. Current can be measured from any point in the plumbing and also the best and closest ground, which could be a grounded outlet or the ground rod to the main panel. Hope that helps!
Yes, it is all making sense. I appreciate your help. I now understand the principle.
I found the below ILL on GOOGLE and it may help someone-