I came across a need to make files in a folder inherit certain permissions no matter who creates them. Thanks to Stack Overflow for help in figuring this out.

You first set a sticky bit for the parent folder, then use the setfacl command to set the ACL:

chmod g+s -R <folder>
setfacl -d -m "g:<group name>:<permissions>" -R <directory>

Example:

Grants all members of group testgrouprw read,write, and directory permissions to /var/www/html/wordpress:

setfacl -d -m "g:testgrouprw:rwX" -R /var/www/html/wordpress/

Sources: