Seems that Andy and Kew agree on the synonym status of Vanilla tahitensis.
To wit: Vanilla tahitensis J.W.Moore, Bernice P. Bishop Mus. Bull. 102: 25 (1933). This name is a synonym. Accepted Name:Vanilla planifolia Jacks. ex Andrews, Bot. Repos. 8: t. 538 (1808). Family:Orchidaceae Original Compiler:R.Govaerts 11/11/2003 Synonymized By: Govaerts, R. (2003). World Checklist of Monocotyledons Database in ACCESS: 1-71827. The Board of Trustees of the Royal Botanic Gardens, Kew. [as Vanilla planifolia] Jose _______________________________________________ the OrchidGuide Digest (OGD) orchids@orchidguide.com http://orchidguide.com/mailman/listinfo/orchids_orchidguide.com