動作環境

Windows 7 Pro (32bit)
SmartGit Version 17.0.4 #10132

CommitペインにおいてTagのpushをしようとしたら、右クリックで表示されるコンテキストに二種類表示された。

Push [タグ名]
Push [タグ名] To

http://www.syntevo.com/doc/display/SG/Synchronizing+with+Remote+Repositories
のPushに説明がある。

Push Pushes all commits in one or more local branches to their matching remote branches. More precisely, on the Push dialog you can choose between pushing the commits in the current branch to its matching remote branch, and pushing the commits in all local branches with matching remote branches to said remote branches. A local branch matches' a remote branch if the branch names match, e.g. master' and `origin/master'. With this Push command you can push to multiple repositories in a single invocation. SmartGit will detect automatically whether a forced push will be necessary.

Push To Pushes all commits in the current branch either to its matching branch, or to a ref specified by name. With the Push To command you can only push to one remote repository at a time. If multiple repositories have been set up, the Push To dialog will allow you to select the remote repository to push to. Also, the Push To command always allows to do a forced push, what can be convenient. This is necessary when pushing to a secondary remote repository for which forcing the push may be necessary while it is not when pushing to the primary remote repository (i.e. the one which is considered by SmartGit's forced push detection). You can also invoke Push To on a remote to push (or synchronize) all branches from the selected remote to another remote.

Pushでは複数のbranchesを一度にPushできるようだ。
masterに対してorigin/masterなどのマッチングを見るようだ。

Push Toでは1つのbranchに関してのPushをできるようだ。
remoteリポジトリを選択できるという点も異なる。
forced pushを行えるという記述もある。