the Bacchus/Dionysus cult once was, according to a source I don't remember, an Amanita Muscaria cult. The brewage they consumed had Muscaria as its main ingredient. Only later, during christianisation, alcohol was introduced as the main ingredient, and Muscaria abandoned.
The Eleusinian mystery cult possibly also used Amanita Muscaria.
I post this under 'Western Alchemy' because there is no sub-forum for ancient Greece/Roman culture.
Edit: ah, I've just seen that Dreamer had already posted about the Eleusinian cult:
viewtopic.php?f=7&t=357