I was requested to come here as it was an RFC..seeing old friends it seems. Anyway, I don't think that quote sufficiently shows that Bon is a sect of Tibetan Buddhism or that it fits those definitions, just that "Bon" refers to a set of beliefs that started to appear under the influence of Buddhism. Isn't it generally recognized that 'bon' believes are quite different than other Buddhist beliefs? Anyway, enough speculation. Powers says" Bon is commonly considered to be the indigenous religious tradition of Tibet, a system of shamanistic and animistic practices performed by priests called shen (gshen) or bonpo (bon po). Although this is widely assumed by Buddhists, historical evidence indicates that the Bon tradition only developed as a self-conscious religious system under the influence of Buddhism." http://www.pbs.org/wgbh/pages/frontline/shows/tibet/understand/bon.html is a very good article on the topic. Maybe can find better quotes there?