Multi-tradition practice is possible, yes (unless you’re part of a religion that has guidelines and/or taboos about that sort of thing, in which case you’ll need to examine those guidelines or taboos for an answer).  Here’s a post sharing some opinions on that in greater depth.  However, in regards to Yemaya or any of the other Orisha, I strongly recommend speaking to a properly initiated priest of one of the Orisha traditions before you begin engaging with her if you haven’t already.