In order to deploy this plugin to the Wordpress Subversion Repository, you need to run ./bin/svn_sync.sh.
When you have successfully completed this operation, you can commit the changes to svn using git svn dcommit
Use SVN to tag new releases, tagging the releases in GIT will do nothing except flag a specific commit. Since we are working with two repositories it is preferable to rather use SVN for keeping track of tags.