A ball that bounces does not beat a ball thrown in the air...if they have the same initial velocity AND the height of the arc isn't crazy. But, again, if the two balls are thrown at the same initial velocity, too high of an arc (or initial angle) will end up in CF and too low of an initial velocity will not allow the ball make it to the bag on a bounce.
Sounds like a good experiment. Set up a pitching machine. Bounce a ball to 2B. Repeat 5-10 times. Then, without changing the velocity or the location of the machine, angle the machine up to make it in the air on a reasonable arc. Record those times and compare. Lower the velocity and repeat. If any of you can make the bounced ball get there faster, I will buy you a beer and a hotdog when we meet. (but first I will give you a lesson on how to operate a stopwatch)
There is one advantage to the bounce, since pop time is glove to glove...if the second basemen can clearly get the bounce but not the straight throw *shrug* I'm just saying that people with stopwatches tend to appreciate glove to glove rather than glove to a miss at second.