A local tag is not synchronized to any remote repository by default - it is kept private to you until you explicitly publish (or "push") it.
Perform one of the following actions:
In the Sidebar drag the local tag onto the remote repository item that you want to push it to.
Right-click the tag in the Sidebar and select "Publish Tag..." from the contextual menu.
In the "Push" dialog select the "Push All Tags" option. This will publish all local tags that aren't already pushed.