The Vodoun spiritual system is an ancient sacerdotal system composed of many pantheons and ethnicities who span the entire West African region. By definition alone, it is not possible to appoint a "chef supreme" of "all of the Vodoun." However, amongst the Fon in Benin, they claim a “pope or chief supreme of the Vodoun”. However, this political title is acknowledged amongst many of the Fon people, but this authority does not extend to the Ewe or other more ancient Vodoun groups, including in the Diaspora who do not have Fon ancestry, or were not initiated in Quidah or Abomey etc., where this title is recognized.
Although the Fon are proud (and should be) of their royal heritage, it must always be kept in mind that there are literally hundreds of royal lineages within the Vodoun clan family system that are not Fon or even of Benin.
It is also important to keep in mind that the Ewe are the major ethnic group and the Fon are a subgroup or cousin of the Ewe. Additionally, the Vodoun has been practiced amongst the Ewe hundreds (if not thousands) of years before there ever was a Dahomey or Benin.
It is further important to note that the Fon descendants who would later establish the Dahomean empire, first originated in Adja-Tado around the 13th century. Adja is the ancient name of the Ewe/Mina groups, and Tado, located in south-eastern Togo along the Mono River, is where the Fon first originated , before fleeing to establish Dahomey and later Benin.
A further less known or published fact, is that the Adangme, were the original indigenous inhabitants of what later became “Dahomey.” They already had a long established running royal Vodoun dynasty long before the Fon ever arrived and, intermarried and overthrew them. Additionally, the Awoamefia, political chieftainship of the Ewe, is still located in south-eastern Togo, of which the Ewe recognize.
In summary, the idea of a “Chef Supreme of ALL the Vodoun” as proclaimed by the Fon, is widely accepted by the Ewe and others as having more political and economic incentives, rather than a historical basis. This belief is widely established in the West, and is also blindly accepted by those who have not done the research. In truth, the Ewe as other Vodoun clans do not travel to Benin to worship or honor any chef supreme. In fact, many often do not even know the name of its latest “chef.”
You can read more here, for more information on the history of Vodoun in Benin and its popular myths.