Bonding a pool is definitely not grounding. Here's the crux of the deal... our power distribution system is designed to have one conductor grounded, or connected to the earth. This is a safety mechanism so that if a short-to-ground of a current carrying conductor should occur, the circuit protection (fuse or breaker) will trip and shut the circuit down. This has the additional effect of placing the earth and the neutral conductor of the distribution grid in parallel, which means that current can flow through both. I was taught that in some areas, over 30% of the actual power distribution current flows through the earth. )I'm sorry that I do not have, offhand, a citation to the source of this percentage; I am pulling it from memory). This is sometimes referred to as stray current or stray voltage.
Think about this - 30% of the current of the US power distribution grid is flowing through the ground, even in some seriously remote areas. Additionally, unbalanced loads on various neighboring installations, bad neutral wiring, improper installations, and other nearby factors can cause even more current to flow through your yard, field, or pasture. If your pool, or pool ladder, or something else you can touch in your yard lies in the path of some of these stray currents, it can become energized to a different voltage, or potential, than other equipment, and present a deadly electrocution hazard should you or your loved ones manage to touch the two at the same time. It is this danger that the bonding system is designed to protect against.
So the two, grounding and bonding, are not the same thing.
Stray Voltage
https://en.wikipedia.org/wiki/Talk:Stray_voltage
Stray Voltages In Dairies
http://edis.ifas.ufl.edu/ae019
A silent killer - Poppler battles stray current for two years
http://dairystar.com/main.asp?SectionID ... cleID=4312