git: push only specific tags

git tag | grep '^v2\.' | xargs --no-run-if-empty  git push <repo>

• .git may not be directory, it may not be there at all. Submodules have there file pointing to root repository. Or you can have GIT_DIR set to somewhere else.
• When no tags match your criteria, you do not want to do the push.

git push <remote> tag <tag>

In your case it will be

git push origin tag v2.*