Is it possible to add KEYWORDS to an Illustrator file to find the file using Spotlight?

I want to be able to find files that have specific content (a certain icon, for example). I've tried adding KEYWORDS to an Illustrator file (FILE INFO > BASIC tab) to see if they were searchable via the Mac Finder/Spotlight, but no hits. Is this even possible? There must be a way - this seems like a productivity/time-saving no-brainer!

For example, I have a vector file that contains a bunch of graphic icons within it; I'm working on another project where I need a certain icon that I know I must have somewhere. Rather than looking through my vast vector collection, I'd like to be able to do an alpha search using Spotlight to see if I already have the icon before looking on a stock site. I thought if I added keywords for each icon within this file, I could find it by searching for the topic name but that didn't work.