Do you have to remove the front motor mount on a 96 Pontiac Bonneville change belt?

No, you generally do *not* have to remove the front motor mount on a 1996 Pontiac Bonneville to change the serpentine belt. While access can be tight, it's usually possible to maneuver the belt on and off without removing the mount. You may need to loosen it slightly to gain a little more play, but complete removal is unnecessary in most cases.