Two comments here, if I can coalesce my thoughts enough.
First, why do we need a Petanque tag at all. There is currently only one tagged question. Search for the name "petanque" and you'll find it. We need tags when we need a good way to help someone track a subject. I'm not suggesting we remove the tag, but just asking for a tag for any sport one person is interested in, for one (or even two) questions will lead to too many (mostly unused) tags.
Second, why do we need a Petanque tag at all, in that that is one derivative of a class of (lawn) bowling sports. If I post a Bocce question, I will want a Bocce tag. Not a Petanque tag. Do we make tags for, literally, every ... single ... derivative sport?
Now, I am going to play devil's advocate to my own comments.
First, why not. Let's make tags for every sport possible. That way if a person posts a question about a very unknown and little played sport, then they'll have a tag to be able to track it. Just because (originally, in the early days of SE) they don't want too many tags, doesn't mean we can't buck that unwritten rule and make several hundred tags.
Second, why not. Let's make a Petanque tag: done. New let's make a Bocce tag, and then a Lawn Bowling, and a Basque Bowls, and a Boccia and a Boules, and every other form or variant of Bowls, and then make a Bowls tag as a synonym for them all.