I probably missed it, but I had assumed that once you could propose synonyms you would be able to vote on them. After I figured out how to propose one it seemed it was the only one in the system until I noticed there were more on the all tab and I eventually found this:
I can somewhat see the point of that decision, but it took a while to figure out what was going on and I still don't think I understand what the "merge" tag is for. I am certain I can find that answer as well, but I would suggest either adding some of this to the FAQ or providing some more obvious instruction or description.
Certainly not a huge deal, but for someone that has only lurked before on stackexchange sites it is a bit confusing.