Does EF allow me to search for award space on all 3 of the alliances? When I do a search, will it pull up all alliance members who have space, or do I have to search by airline and route.

I've got a lot of miles I intend on using over the next couple of months/years. most of them are in United. I intend to be traveling to Africa and Europe primarily. A trip to South America on AA miles is also in the future