There have been several retrospectives since Bob Dylan won the Nobel Prize for literature. WNYC has posted Dylan’s first radio interview from 1961 (18 min) .
The Library of Congress hosted a video lecture about Dylan’s decision to switch to electric guitars in the 1960s.
A BBC radio documentary “Ghosts of Electricity”
A BBC Radio documentary “Highway 61 Revisited”
C-span debates “Bob Dylan in America”
Fora.tv debates “Bob Dylan’s poetry”
On the radioshow The Mind’s Eye “Dennis McDougal discusses his book “Dylan: The Biography.””
The only decent documentary on Dylan I could find was a BBC Omnibus special from 1986