I think this trick was definitely viable in 3e, but I'm not sure it would actually work in 3.5e.
Teleport allows you to teleport "touched objects or other touched creatures"; the number & mass of objects is limited by your maximum load, and the number of creatures is limited by level. I don't think putting a creature in a bag (or a bag, or probably even a portable hole) turns that creature into an object, and if Creature-In-Bag is still a creature, then the limit on number of creatures still applies.
If Creature-In-Bag is an object -- well, that would open up some interesting situations, no? There'd be a number of spells they'd be immune to, and (IIRC) some spells they could then be targets of -- for example, shrink item on people, anyone? Plus, the people in the bag/hole/whatever wouldn't get saves; they'd have to rely on the saves of the item (if it wasn't being held or otherwise "attended") or the person holding the item (which would often be a wizard, rogue, or the like; could be tough if an enemy wizard zaps the bag with a disintegrate while some low Fort save type is holding it).
I once ruled (in 3e) that an archon could teleport with a bag of holding containing a person (in this case, a child); but I later decided that I was probably wrong.