Drupal-git-sandbox project: commits are shown but no new revision
Sandboxes on Drupal.org can't have releases (tagged revisions).

For a full project, if you want to push a specific release/revision, rather than just a SHA-identified commit, you create a tag locally before you push a tagged release.

git commit -am "Revision 7.x-1.0"
git tag 7.x-1.0
git push origin tag 7.x-1.0