Put domain name in php-fom pool name
http://www.howtoforge.com/forums/showthread.php?p=307449
Or make <tmpl_var name='domain'> available in php_fpm_pool.conf.master
http://www.howtoforge.com/forums/showthread.php?p=307449
Or make <tmpl_var name='domain'> available in php_fpm_pool.conf.master