It seems lots of people are having trouble getting Spotlight to find stuff in iPhoto. While it's not so difficult to open up iPhoto and just search for something in there, it kind of defeats the purpose of Spotlight in general. Unfortunately Spotlight doesn't use all metadata available in indexing. In particular, it doesn't use the film roll title. Making matters worse, iPhoto doesn't give you an easy to rename files. Worse still, if you rename a file manually iPhoto freaks out. If you rsync your iPhoto collection across two or more Macs like I do things are worse even still. All the metadata is there, but Spotlight doesn't import it anyway even if you try to forcibly
mdimport the iPhoto Library.
I have discovered a solution.
Basically, if you mark a new keyword on an image and then quit iPhoto the metadata will be reimported into Spotlight. I created a new keyword called Spotlight, select all images set the Spotlight keyword and then quit iPhoto.
I had a spotlight search open for "Russia" and my Stolichnaya desktop pics instantly popped into the search results.
After your pics are successfully imported, go back in and clear the Spotlight keyword on the pic. Then any time you need pics reimported just add the Spotlight keyword on, quit iPhoto, then remove the Spotlight keyword.