I believe the bus ride to DS is about 10 mins from Pop but can vary depending on the traffic at DS.
All buses at Pop pick up in front of Classic Hall. The stops are next to one another with clearly marked destinations and queues. The one second furthest away from the entrance doors to Classic Hall is the Disney Springs queue. In the picture below the DS stop is the one under the red POP furthest to the left.
View attachment 563076
All buses drop off and pick up at the same location at Disney Springs. In the picture below the boat launch for POR is top right. The bus stops are bottom, centre. Basically the complete opposite side of DS from one another.
View attachment 563077