I have a scenario in which there a several remote tracking branches within my local repository that I must sync up to. Our workflow model is:
Git does not track what branches a commit was put through. There is no way to tell. If the commits happened on your repo, then you can inspect the reflog, but that's about it. Take a look at the explanation of the DAG in the Pro Git book - also read up on reflog in there.
You can also visualize history better with gitk --all or git log --graph --decorate
Hope this helps.