Stand is supposed to exhaust the developer in the highlight areas so they don't blow out. It also provides more fresh developer to the shadow areas to fully develop these areas. This is achieved by not agitating the used develop out of the highlight areas, and leaving less used up developer in the shadow areas. Generally, it is used for scenes that have a large number of stops (very high contrast), too many for normal development. So I guess you would not use it on controlled, lighting indoor, overcast day, or other low contrast scenes.
Two Bath development is somewhat different. It is suppose to temper highlight development while encouraging shadow development, sounds the same to me. But somehow, it is suppose to bring all contrast scenes on the same roll into proper development. They say it is achieved by #1 what I said in my second sentence, and #2 by giving the mid-tones more contrast in flat scenes and not so much in high contrast scene. Read up on Barry Thornton for a better explanation of Two Bath.