Lost association between TAGS and COMMITs when rebased a git(1) repository

With my first use of git(1) I created a small project with about 200 "commits". When this was complete, I needed to label each commit with information pointing it to a section of a document. I used tags for this. So far, everything was fine. I was then asked to merge two commits into one. I then did a "rebase" (for the first time). I then appear to have lost all association between the tags and the effected commits; as all commits after the ones I modified no longer see "their" tags. Was there a way to have kept the tags associated with the original commits as they were "rebased"?

Also, I have some commits with multiple tags pointing to them. It has come to my attention that might not be an intentional feature. I could find nothing in the documentation explicitly stating multiple tags were allowed to point to a commit; but the tags seem to be unique "objects" so I see no reason this should not be an expected feature?

Thanks for any insights. Other than loosing association between the tags and the commits with rebase (which I was hesitant to use; and am now doubly so) I found git(1) to be the first version control system better than "be careful and make tar-balls of major releases"; although I am just starting to get an idea of how the pieces work.