Fourknots, when he says bonding I think he means bonding the mast (and shrouds) to the keel if you have an external lead/iron keel and not necesarily the thru-hulls.
Seperately, the reason you might want to bond the thru-hulls is to prevent their deterioation due to electrolysis or galvanic corrosion, but like you said that has nothing to do with lightning strikes.
BUT, if you were on a boat and your boat got hit with lightning, you (or your loved ones) have a MUCH better chance of not getting hit by the lightning or side-flashes if your mast/shrouds are bonded/grounded.
If you are on a boat, especially a deck stepped one, and the lightning comes down the mast or shrouds and then has nowhere to go (since you didn''t bont it to the keel) then you are just as good a conduit of that electricity as the air is (maybe better!).
To me, that is the best reason to ground/bond the Mast/Shrouds to the keel. (I wouldn''t bond to the thru hulls).
I think the website/article he refernces alludes to that also. Its more for safety IF you do get hit.