Pretty much all the buses from outside Stoke station (turn left out of the main doors) go to Hanley.

From Hanley bus station definitely the 20 and the 21 (maybe even some other 20s) go through Burslem.

You can get off the bus just after the big crossroads outside a strange modern building called Ceramica. From there it's a shortish walk (5 mins). There should be people wearing Vale shirts who you can follow.