1st of all it depends on what the gravity is when you racked. As fermentation slows there is no sugar to eat and turn to alcohol. The bubbles will get smal;ler and smaller. This alone does not mean its finished. This is why we say to ck the gravity 3-4 days in a row. Wine should end around .990
So if you racked lets say @ 1.010 you may noe see any bubbles they may be very fine ones