The set bonus definitely works with Galvanizing Ward, but I'm not sure if that's the only spell/passive it works with.
As for which one is better, it depends entirely on what you're going for. Chantodo's Will has more damage and has Life on Hit. Neanderthal, on the hand, has Vitality and thorns. If you find yourself taking lots of big hits, then perhaps you want to go with Neanderthal for the life boost. However, if you generally avoid getting hit and only need a bit of recovery in between and during fights, Chantodo's is probably the better choice.