A fishing license is required when fishing on Toledo Bend Reservoir. Since the lake is bounded by both Texas and Louisiana, a fishing license from either state is valid for residents of either state fishing on any part of the lake (not from the shoreline!). For visitors who will want a temporary license, where you are staying (Louisiana side or Texas side) is not particularly relevant so long as you will be fishing on the lake and not from the shoreline. Therefore, generally, you may be staying in Louisiana and could fish with either a Louisiana or Texas temporary license - or vice-versa.
Bag limits are the same for either state on Toledo Bend.