Nope, nada, zilch. Traditional Wing Chun or another transliteration - Ving Tsun, Kung Fu, as developed by the venerable grandmaster Yip Man, offered no belt or sash rank as I have learned it. The more traditional family versions of Wing Chun to this day do not. You train to train, period.
At the time of his departure for the states at a very early age, Bruce Lee was not yet one of grandmaster Yip Man's senior students, but certainly a very talented one as the story goes.
Essentially, you are accepted as a student into that WC family. As you progress, you grow into martial maturity and can become a senior student, "big" brother or sihing(something akin to sempai)Ultimately, upon retirement of the Sifu(father), his death, your relocation, expansion of the kwoon, or special circumstances, etc., you may progress to Sifu. That's it so far as promotion goes. Until you progress to sihing or sifu, you small fry!
Of course, the honor of being accepted into a WC/kung fu family was and still is a very big deal in and of itself. (It's a little like karate before Kano - the guys with the dirtiest, worn gi's and obi's were the advanced students.)
As I understand it, Bruce Lee sort of had to leave Hong Kong for mysterious reasons , but that's another story ...