I should say that, in addition to using the word “Mormon” once, Romney did mention Brigham Young by name, to put him in a group, including Ann Hutchinson and Roger Williams, who were denied religious liberty.
Personally, I think Romney over-emphasized the place of religion in American political life. It’s not a matter of excluding atheists – that’s not a big deal, although Romney could have easily included people of no faith in his discussion. Rather, the more important point is that one can be religious, can attend church regularly, and still believe Romney attached too much importance to religion in American politics.