and the master of the banquet tasted the water that had been turned into wine. He did not realise where it had come from, though the servants who had drawn the water knew. Then he called the bridegroom aside
The master of the banquet was the man in charge of the seating of the guests and the running of the feast. Note the eyewitness account given here as to who knew what. John was present and is writing what he remembers. The master of the banquet calls the bridegroom because the feast was put on by the bridegroom’s family.
As Bengel says: “The ignorance of the ruler proves the goodness of the wine; the knowledge of the servants, the reality of the miracle.”
Everybody at the wedding feast benefitted from the miracle of changing the water into wine, but only a few received the full benefit because they knew the source — the disciples, whose faith was increased and the servants. The disciples were qualified to be blessed by the miracle because they were followers of Christ; the servants received because they obeyed.