… are wholly unrelated.
holistic is borrowed from Greek ὅλος "whole" (as in catholic) from Proto-Indo-European *solh₂- "whole".
whole is from Old English hāl from PIE *kailo- "whole, uninjured, of good omen". Also from this root are German Heil "health" and Irish Gaelic cel "omen".
whole began to be spelled with wh in the fifteenth century, apparently due to a dialectical pronunciation with /w/. It also happened with whore.