Looking to crank out max damage on a Cavalier build, and doubling Power Attack (with Wild Flanking) seems like a good way to do that if I'm using Spirited Charge and a lance. The only problem is dealing that much damage to my allies. 1x is manageable, but 3x-5x Power Attack is way too much.
Does the bonus damage to my allies from Wild Flanking get multiplied by Spirited Charge/Lance/Critical hit?
Yes, it's a flat bonus rather than dice and it's not precision damage. It gets multiplied.
That is why you have a caster provide a summoned monster for the flanker.
/cevah