Nope. A small bonus for staying grounded would be just as useless as the small bonus from being in world mode.
"OH BOY! 9 EXTRA GOLD FROM THIS WQ!!!! WAR MODE IS AWESOME!!!!"
Versus
"I spent the extra hour farming instead of partaking in pvp. All these herbs will make me thousands on the AH. But clearly horde bias because they get 9 extra gold on their wq's amirite?"
and
"OH BOY! 9 EXTRA GOLD FROM STAYING GROUNDED! GROUND MOUNTS ARE AWESOME!!!!"
versus
"Instead of spending an hour just in travel time from one wq to another, I spent that hour farming. And because my movements speed is slightly more than triple the grounded folks, that extra hour spent farming was ~3 times as efficient as before. Now I'm making tens of thousands on the AH. but clearly ground mount bias because they get 9 extra gold on their wq's amirite?"
Anyone who cares about gold making doesnt go warmode because the bonus is little more than a pittance. And they would enable flying, because it would still drastically out pace staying grounded. The bonus would have to be monstrously absurd for anyone to choose to stay grounded.
So no, it wouldnt be a solution.