1) The relevant metric is net income not revenue (that's what at stake for them)
2) Those figures are worldwide, not just for Mexico.
That said, I wouldn't be surprised it's not Coke and Pepsi directly behind the spying, but FEMSA and other bottlers. After all, why would Coke risk its huge brand when the bottlers, who have as much as stake, are Mexican, and are thus better to "influence things over there"