>> I am just wondering how compatible this would be with Satanism's tenants. <<
The Church of Satan
is not a great big housing block full of rooms we rent out. So we do not have tenants.
Perhaps you mean tenets?
No, membership of the Freemasons would not exclude anyone from also being a CoS member. Indeed, we have members who are also Freemasons. Though individuals themselves may well have incompatible views.
"Spiral Out: a bleak, page-turning, unforgettable read. Existentialism at its most hardcore" - www.uvray.moonfruit.com