At the first Bush Inaugural. That's when.
So, it turns out that Bush was for singing "The Star Spangled Banner" in Spanish before he was against it. Details at Think Progress. But wait! There's more. Bush himself used to sing the anthem in Spanish when he was on the campaign trail.
Of course, my favorite morsel in this whole episode is Bush saying the other day, "I think people who want to be a citizen of this country ought to learn English." Goes for people who want to be a president of this country too, dontcha think?