Wood, plastic, aluminum, lucite, stone, rubber, steel, glass, titanium, it's all good, but CITES does not make tone woods illegal or forbidden, it places restrictions on the source and movement of woods like Dalbergia Nigra (brazilian rosewood) or Swietenia Macrophylla, (broad-leaved mahogany or honduran mahogany).
Not many bassists have instruments with those exact species from the controlled sources/countries and imported from after the restrictions were instituted (the date when the species is listed in Appendix III). N.B., Swietenia Macrophylla is widely grown for consumer uses outside of the americans, especially in asia.
Gabon Ebony is now part of the story. Diospyros Crassifora (and dozens of other Diospyrosia) were listed in Appendix III of CITES in 2011. These species are now endangered. See above for more detail on CITES Appendix I, II, and III.