The name of Tibetan Buddhist Rimé·རིས་མེད་ movement is often translated as ‘non-sectarian’, and the movement is misunderstood as ecumenical, meant to unite all Tibetan teachings, both four major schools of Tibetan Buddhism as well as Bon in a form of some kind of a new age movement.
Modern followers of Bon are also often very willing to take advantage of superficial resemblance between Tibetan Buddhism and Bon as well as lack of knowledge among Westerners fascinated with exotic Tibetan culture to market their religion as another school of Tibetan Buddhism.
There is also a common myth that bonpos and buddhists both belong to ནང་པ་, practitioners of ‘inner path’ as opposed to ཕྱི་པ་, a term for tīrthika, the followers of non-buddhist religions.
Recently I’ve stumbled upon an example clearly showing that Rimé movement has nothing to do with ecumenism, and that bonpo were not considered to be buddhists, but quite the opposite, are mentioned together with tīrthika by none other than Jamgon Ju Mipham Namgyal Gyatso·འཇམ་མགོན་འཇུ་མི་ཕམ་རྣམ་རྒྱལ་རྒྱ་མཚོ་ who is considered to be one of the leading figures in the Rimé movement.
In his commentary on the Madhyamakālaṃkāra·དབུ་མ་རྒྱན་, the homage to the Buddha that is traditionally put in the beginning of every Tibetan Buddhist text, contains the following line:
A gathering of wild herbivores – bonpos and tīrthikas of the Noble Land [of India], the Cool [land of Tibet] and other places, dwelling in the valleys of views of self…
It is not to be understood that bonpos are literally called wild herbivores here. The context is that they are frightened at the sounding of the name of the lion-Buddha. However, bonpos are clearly grouped with non-buddhists.
Incidentally, the English translation of the commentary by Padmakara Translation Group prefers a more elegant phrasing ‘like antelopes’ here, even though several lines below in a similar passage that mentions only tīrthika the same word རི་དྭགས་ is translated as ‘wild beasts’.