Google and Yahoo/Bing are very different search engines and have their own ranking systems. That is why optimizing for Google does not increase Yahoo or Bing rankings, in general.
Years ago I also tried to optimize my websites for Yahoo and Bing. But I found that those common optimization methods were not effective. Even when I just added my websites to bing webmaster tools, many pages of my sites could not be properly indexed there. Finally I gave up, and then focus my time on mainly Google ranking. I believe Yahoo or Bing will not bring much traffics to my sites anyway, so it's not worth my time to focus on their ranking.