I think you have confused things a bit.
So on PE1
you will add another vlan tag of 100 when traffic ENTERS the interface (Ingress).
This gets to PE2 (hopefully)
the process works in reverse. So you would need
encapsulation dot1q 30
rewrite ingress tag push dot1q 100 symmetric
Traffic will enter the service instance and dot1q tag of 100 will be removed.