Most SEO's I speak to and it's something I have said. Optimize for Google and you'll be good in Bing and Yahoo.
In this case though something appears to be missing or preventing Bing positions.
Read the best practices guide for Bing and also sign up to Bing Webmaster Tools to get a better understanding on how your website is being indexed with Bing, you will see how many times your site results for a long tail search term, where in the results it was positioned and how many times your site was clicked for that term.