Just to add, no Buddhist has any authority over any other Buddhists anyway. Not as Buddhists. We don't have Popes. Nobody can change a single word of the monks and nuns ordination vows, for instance. They want to, the traditional nun's ordination vows seem out of place in a modern society, many Buddhists worldwide would like to change them.
But there is no mechanism available to do that. What the Buddha taught, and his sutras, can't be changed.
What the Dalai Lama can do is to offer his own elucidation of the Buddha's teachings. And make suggestions. But even amongst Tibetans -though he is widely regarded as inspiring, they would not for a moment think that he can tell them what they should believe or how they should behave. He could only say that to his own students, the ones he has known for years who go to him for personal help and advice. And for them also, the aim of the teacher in Buddhism is to help his students find out the truth for themselves. For instance if a teacher tells a student to do something that goes against the teachings of the Buddha, as the student understands it in his or her heart, then he is rightly ignored, no matter how long and close the connection they have.
Of course this depends on the understanding of the student also. But aim of the teacher is to waken that understanding in his or her students. And help them to find the truth for themselves, whatever the truth is for them.
That's just how it works in Buddhism. The Buddha said not to take anyone else as the leader of Buddhism after he died, but instead take the sutras as our teacher. And to find out the truth for ourselves. And the Buddha's own teachings - though we think they have great blessings associated with them - still they are just suggestions and hints, and not "revealed scripture" as in many other religious traditions.