Taneshia is simply an alternate spelling of
Tanisha.
Tanisha is a name which became popular in the African-American community because of the actress Ta-Tanisha, but so far I have been unable to determine where she obtained her stage name. It is possible, as this site speculates, that it is simply an elaboration of
Tania using the -isha suffix that was very popular in the African-American community at that time.
http://www.imdb.com/name/nm0845814/