Victor Smith turned me on to this article with this blog and I thought it was so good that I had to post it separately. I've met Charles in person and used the library of rare books he donated to the University of Hawaii at Manoa and I believe that this is truly a treasure for all karateka. It's the largest collection of rare karate books on Earth. This article represents one of the best pieces discussing bunkai that I've read. I love that it is Hawaii specific and that he discusses this from the island perspective. Check it out!
http://seinenkai.com/art-bunkai.html
http://seinenkai.com/art-bunkai.html