This brief tutorial will walk you through the steps involved in installing and using/understanding Ziplight, a plugin that enables Spotlight to search within .zip files.
Now you have to wait a while as Spotlight updates its database. Eventually (after about 30 minutes for me) when you perform a Spotlight search, files inside of .zip files will begin to appear in your search results. NOTE: Ziplight won’t enable Spotlight to index the actual contents of the files inside of .zips, just the titles of the files inside .zips.