In default git remote configuration you have to push tags explicitely (while they are fetched automatically together with commits they point to). You need to use
$ git push <remote> tag <tagname>
to push a single tag, or
$ git push <remote> --tags
to push all tags.
This is very much intended behaviour, to make pushing tags explicit. Pushing tags should be usually conscious choice.
Alternatively you can configure the remote you push to to always push all tags, e.g. put something like that in your .git/config
:
[remote "publish"] # or whatever it is named
url = ...
push = +refs/heads/*:refs/heads/*
push = +refs/tags/*:refs/tags/*
This means force push all heads (all branches) and all tags (if you don't want force pushing of heads, remove '+' prefix from refspec).