According to this recent discussion on the PHP-FIG mailing list, the Yii framework project has tossed their hat into the ring and joined the PHP-FIG.

As Alexander Makarov writes in his post:

I'd like to apply for voting membership because I feel that fig is very important and that I have enough experience to make the final result better.

All of the votes from current members have been "+1" for the project's inclusion into the standards group including ones from several other well-known projects (like Zend Framework, PEAR and Doctrine).