except for the motorand those braces, everything will be non - metallic, buried, and concealed by plants and more rock.
scraping off that bedliner, getting a good bond and successfully recoating submerged galvanized steel seems like a waste of time, since those connections will fail eventually and are under water anyway.
besides, someone would have to get into the water before they could touch any of them
there is no concrete walks, railings, or re-rod within three inches of the water so an equipotential plane and the required bonding would seem unnecessary .
the terrain around the large pond is terraced which makes the three foot rule hard to meet but again there are no metallic parts near these ponds and I will drop a ground rod by the first j-box that feeds the pump, and probably add a couple more rods just to err on the side of caution...