A spiritual master must be in an authorized disciplic succession to be bona fide. It is not possible for someone to be a bona fide spiritual master in a line of spiritual authority that does not come from Krishna. Sometimes pseudo-spiritual masters create a line of philosophy. They have a “vision” or dream in which they imagine that they have become empowered by God, or that they are God, and they should start teaching others. But this is never accepted by the true followers of the Vaishnava tradition.
There are four Vaishnava sampradayas, or bona-fide disciplic successions, in this universe. The first is the Brahma Sampradaya, or school coming in the succession from Lord Brahma, the creator of the universe; the second is the Rudra Sampradaya, coming from Lord Shiva, the destroyer of the universe; the third is the Sri Sampradaya, coming from Laksmi, the goddess of fortune and constant associate of Lord Vishnu, the maintainer of the universe, and the fourth is the Kumara Sampradaya, coming from the four Kumaras, who are incarnations of devotional knowledge. Knowledge received from these four sampradayas is eternally correct and will bring you back to Godhead, whereas knowledge received outside these sampradayas is temporary and will not bring you to the highest destination.