I think I'll open this up some more to incorporate more.
Christianity, Islam, Judaism, Hinduism, Buddhism are in the ATL major religions, however they are'nt all necessarily the same, for instance Islam may not be split primarily between Sunni and Shi'a and Christianity may not have Catholicism, they simply have to have the basic beliefs, also another thing I've though about, they may not geographically be in the same places, for instance while Christianity is going to go into Europe, since it's a very good area for an agricultural society, Islam may not spread primarily into the Arabian peninsula and North Africa, in fact I can see it spreading into parts of the Arabian peninsula, primarily coastal areas, but primarily spreading North, into Central Eurasia and perhaps spreading East in the lower part of what is now Asian Russia.
North America being Christian is a given, since most of the Native American and thusly their religions were eliminated by the Europeans, either through the spread of disease or genocide.
South America is less so, I can see their being a more local variant of Christianity that while keeping the core beliefs may develop and adopt more local customs and beliefs.
One other thing, so long as it's against eating most or all animals you could come up with an idea for a additional major religion, perhaps that encompasses parts of Africa.