I do believe it's possible for pantheism to be more relevant to an atheist. For example, many theists believe in god as a literal deity, a.k.a. the guy with the white beard. Therefore, the idea that god is everything, and everything is god, suggests that he is not literal, but more of an unseen force. Similarly, atheists might interpret pantheism as more of a description than a method of worship. The universe, and everything in it, is incredibly beautiful and mysterious. Pantheism may just be assigning the word 'god' to describe that beauty and mystery. As an atheist, I've frequently referred to incredible things as divine, but it's not because I believe they have any connection to a god or heaven, it's just that normal words do not describe something's majesty. But, that could just be because I'm a writer, and I see all of these as words first and religious associations second.