Well, we're talking bi-amping vs bridging... so the apples to apples comparison is 140W per side vs 200W per side, right?
You might notice a slight bit of improvement, but it depends on the speakers, really, if they can handle more power, or if you're just going to be losing it to power compression, heat, etc., and if you might blow them.
Just going by the theory of power-to-volume, going from 140 to 200 is probably only about 1dB difference, barely audible. Again, that's just a theory... I think it'll be somewhat of a push either way.