Vacuum does not collapse bubbles in the line. It can expand them if enough vacuum is applied. Typical vacuum bleeders bleed by attaching to the bleeder valve on a slave cylinder. When vacuum is pulled on the open bleeder, it draws fluid out along with the air. The fluid is replaced by fluid in the reservoir. Once all the air is flushed out the slave bleeder is closed and it is good to go. If you have bad seals anywhere, vacuum can actually draw air into the system.
The problem with bleeding a clutch is the master cylinder is at an angle and air can get trapped with no way of bleeding it with out removing the master cylinder to rotated it to a position that will allow bleeding of the air.
2002 FX4 Bright Red Supercab 4.0 SOHC, manual 5-spd & Tcase, 33" BFG MTs, K&N air filter, Modified air box inlet, Gibson SS cat. back exhaust, Bama flash, Hidden Hitch round receiver, Rear helper air springs, Electric trailer brake controller, Line-X bed liner, WAAG bar with KC lights and Wildernest shell.