a Raven is a plain bird, not considered something very nice or anything like that, while a Phoenix is more or less the "bird among birds", a mythological creature ... seems a bit unfair, but maybe that's only my impression?I wouldn't use these two together. On their own I like them though.
I'm going to agree with Minikui. If you're going for fantastical names, why not go with Griffin or Drake? They're both flying creatures from myth and legend. (although Drake is a duck too.)