According to Henry Archer, in his book The Magick of Angels and Demons, Bune’s real name is Bime, and he is a male demon. Bime only became Bune due to mistakes in the Crowley-Mathers translation of the Goetia. The female Bune is a modern invention.
Astaroth is a male demon, and always has been. The only connection to a female form is one forced by occultists, due to some linguistic similarities between the name Astaroth and that of the goddess Astarte, though how the mere fact of the same few letters in the names equals to them being the same spirit is beyond me. Logically, that’s like saying everyone whose name is some derivative of “Chris” is the same person. Doesn’t make much sense.
While it is true the Christian conquerors, like other conquerors before them, demonised the gods of the conquered, the demon Astaroth doesn’t even have the same power set as the goddess Astarte so the occultist trend of claiming them as the same being is very dubious.