I would like to know if the Rastafarian religion has been accepted into our constitution and if it has, what kind of legal implications there are towards there practice and rituals

The US constitution says: "Congress shall make no law respecting an establishment of religion, or prohibiting the free exercise thereof" so all religions follow that rule.

Soooo... you're trying to figure out a legal way to smoke weed?

There is no religion that is listed in the constitution. The only rule for acceptance of religion is if it is accepted by the IRS as tax exempt.

Beyond that even religions that are accepted as tax exempt can not do anything that is against the law.
IE, no pural marrages for those religions that accept them.