Perhaps, but syncretic nation states/cultures are
Why does it have to be dominated by one culture? Perhaps the French and English cultures would merge to become one, with the differences between them being merely linguistic (though to a lesser extent than in OTL, with the French and English languages mingling).
Certainly you're going to end up with a very powerful European empire that will be a much stronger rival to Spain in the new world.
Perhaps, but syncretic nation states/cultures are rare in the modern era; what would be an analogy in Europe since 1500?
France, perhaps, if you consider the linguistic divides (Provencal, etc) , but those are significantly closer than England and France would be, even in the 1500s.
Spain - hard to see an Anglo-French (Franco-English) polity forcing unification at swordpoint, but at least they would not have the religious issues - at least until or unless a Henry VIII-type figure came along. There there's Ireland...
Italy and Germany, I'd suppose, but those both formed as such much later.
Best,