Well today I finally figured out how to do what I really want to do. Instead of creating a separate tag for each event, I can simply construct a URL that performs a dynamic search for photos that match multiple criteria. For example, the URL
displays the same collection of photos, assuming the photos are tagged with container and salsa. I prefer using generic tags so I'm in the process of removing the old event-specific tags and replacing links with dynamic queries like the one above.
The only drawback I have found to this way of linking to my photos is that the search results page displays advertisements from Yahoo. I guess ad-free search pages aren't included with my Flickr Pro membership.