I'd agree on paper. I'd say it's clear the reigns of English are firmly in control by what happens in the USA. And Spanish is likely at the point, due partly to its rise in importance as it increases usage in the US, leading to Mexico being the world's canonical source for Spanish. You couldn't tell an Englishman or Spaniard this, but I'd bet most international students aren't looking to emulate how they speak in England or Spain, but rather the US, Mexico or Columbia. As a second language speak of Spanish myself, I know I would greatly prefer to blend in more in Latin America than in Spain. It's just a larger part of the world.

Ultimately the US was founded by English speaking people, just as Mexico was by Spanish speaking people. These languages are as much ours as they are Europe's. But we both definitely dictate the ultimate future of both languages now out of sheer numbers and economic influence.