With only two meetings under my belt, I'm not qualified to speak about the spiritual dimension of the group.
I will say this: as an atheist, I've been welcomed with open arms, and the focus has been on sharing rather than excluding, and that has always been a spiritual principle of mine (yes, I'm a spiritual atheist, in the sense of awe at and connectedness with the Universe). The spirituality I see evinced in the groups I've attended was not doctrinal or dogmatic, but rather, seeing people in touch with themselves (to a greater or lesser degree) reaching out to touch each others' lives.
Ain't that as good as it gets?