The 20th Anniversary edition of Vampire: Dark Ages builds on the efforts of Kindred of the Ebony Kingdom to develop the vampires of Africa into a standalone society rather than a single clan. That's why they took the word "Laibon," once used to reference a Kindred bloodline and there after the African sect of vampires, to be a generic term for an African undead, like "Kindred" or "Cainite."
The Bonsam — whose name echoes the Asanbosam vampire myths of the Ashanti — have Animalism, Obfuscate, and Abomwe. In this way, they are reminiscent of the Nosferatu of VtM, except with their custom discipline replacing Potence. Their weakness incites fear in those who look upon them. References to their "true form" do not mean "unshapeshifted"; they mean "unconcealed by Obfuscate."
Although the printed image may suggest a batlike mien, and their language is composed on "whistles and shrieks," there's no evidence that they derive from the Camazotz changing breed.