What's the best way for a person without tag privileges to suggest a new tag? In this particular case it's about tag "Bulgaria", which I believe doesn't need further explanations. I couldn't find any way to do that in FAQ or tag guidelines.
I don't think there's an "official" way. You can add a comment under the question (I frequently see those) requesting a tag; or flag your question for moderators, or as you did ask on Meta. All valid approaches, though the first one us likely to be most streamlined as more people will see the request faster.
Meta is preferable if you aren't sure if the tag should be created.
They typical way is to just type the new tag name into the "tags" field of the question. However, you have to have enough reputation on the site to do that. I'd have to go look up the amount required here on a beta site, but I'm pretty sure its more than your current 65. :-)
As DVK says, asking on Meta is generally a good idea too. Often times there is a similar or even synonamous tag already. Probably not in this case though.
Since we've created the tag, care to propose an initial wiki summary for it? (Feel free to answer as a comment to this answer).