To actually answer the question, 115 watts of fluorescent should be enough to take 2 plants through flowering, if you don't grow them too big and don't need too heavy of a yield from them.
Unfortunately, to create uniformly viable seeds usually takes a lot of light; either true sunlight or high-power HPS type lighting. You certainly can get seeds under your 110 watts, but under that relatively lower intensity of light the seeds may not be fully developed and many of them may not sprout.
The problem is that if you go to the trouble of fertilizing your female plant(s) and the seeds aren't viable, not only will you not end up with good seeds, you'll also not have much quality weed to show for your 3+ month grow. Its sort of the worst of both worlds.
You might consider topping or otherwise training your plants to create multiple colas and then trying to only fertilize the one(s) closest to the light.
With fewer seeds to grow, the plant can devote more energy to those few, increasing the likelihood that they'll be good. Also, with some unfertilized tops, you'll also have a better chance at getting some quality herb along with the seeds.
Don't even bother fertilizing bottom branches, since they probably won't create mature seeds. In fact, you might want to prune off any lower growth here.