I'm not exactly sure on this but I'm not positive that this has been demonstrated in vivo with humans though it very likely has this effect. Also keep in mind that different cells in the body have different rates of turnover which likely carries over into the mitochondrial dynamics. Supposedly, resveratrol also promotes mitochondrial replication.
I may be wrong, DSade would know better, but the benefit would likely be only for higher reps where lactic acid starts to become an issue since the effect of more mitochondria would be increased ATP production. I don't think ATP is typically a limiting factor with strength in the lower rep ranges. Again though, I'm not positive on this and may be off. Been awhile since I've studied this stuff.