There are four or five possible direct correlations between the title of section three, and events that occur in that section. They are of Montag's house "burning bright" as it is torched, of Beatty "burning bright" as he dies, of Montag's entire city and society "burning bright" as planes destroy it with bombs, and that of the symbolic Phoenix spoken of by Granger "burning bright" once again as their entire way of living is wiped out and burned, making room for him and Montag and their group of outsiders to come in and rebuild it. Symbolically, Montag's future is "burning bright" as he moves with his new friends to attempt to build a society that won't make the same mistakes as the past one did.
At the beginning of section three, Montag shows up at his house, only to discover that the firemen have been called there--by his own wife--and that it is going to be burned down to the ground. Beatty has Montag himself torch it; after he is done, "the house fell in red coals and black ash." His life as he knew it was gone. Then, when Montag cracks, he burns Beatty also; Beatty becomes a "shrieking blaze" before he dies. When the city is burned, it goes up in a large fireball, a "flourish of light." Granger describes how the Phoenix "burnt himself up" only to be born again, new.
Overall, the burning bright is a symbol, a tie to specific instances, where everything that Montag ever knew is completely destroyed, through fire, burning bright as his life is wiped clean. I hope that those thoughts help! Good luck!