so, i dabble a lot in greek mythology and I was looking at the story of adonis and aphrodite. On wikipedia it says he also had some Mesopotamian roots, which involved him (his name was dumuzid/tammuz) and his wife: Lord innana. Since I know lord innana is real it made me wonder if tammuz was real, so I looked through the demons lists and even the runes and saw nothing. Is he just another allegory?

Tammuz has striking similarities to the Hades/Persephone story. Alternation of season, spending half the time in hell, etc ,etc. While he may be an entity, within his mythological context he is an allegory. As for what that allegory is I'm going to do an academically risky thing and extrapolate from the Hellenistic Hades/Persephone myth.
H/P right off the bat gives us a male female pair, this is an important spiritual concept as the chakras are gendered and paired.
Hades has a bident, which has been debated as to what it means, I do assume it represents the merging of the Ida and the Pingala (once again a male/female dichotomy)
As for Persephone (eg tammuz and his sister) spending half their time in the underworld and half in the (over)world(?), I do believe this represents the lower chakras and the upper chakras respectively, and how both male and female energies must exist in a balanced state within all seven main chakras.