I've never had a clutch master cylinder fail on any of my Alfas, but I have to replace a slave at least once every few years on all of them. Must be the dirt/muck down there that gets into stuff.
I'm also a fan of gravity bleeding. Just put a line on the slave, make an inverted U, put the other end in a bottle, them fill the resevoir and wait. The fluid will make it's way down and the bubbles up and eventually fluid comes out.
Good luck, bleeding clutches can be frustrating.
Ian Lomax - Current: 1973 Berlina, 1987 Milano Platinum "racecar"
Past: 71, 74 Spiders, 2x 74 Berlina, 74 GTV, 76 Alfetta GT, 88 Milano 3.0, 164LS