Have you been greasing your pivots and bearings?
Even if things are adjusted properly, you can get some creaking from dry pivots.
SC's VPP suspension needs to be maintained. You can get slop/knock/flex when things aren't tight.
If the shop correctly adjusted things, there should be no flex.
Tech Tuesday: Adjust the Pivot Bearings on Any Santa Cruz VPP Suspension - Pinkbike
The above procedure is easy to do yourself.
Lube the pivots and bearings and adjust things like the video shows and see if that fixes it.
You said pulled wheel "forward and back" and noticed a bunch of flex.
Did you mean side to side?
If you grab a seat stay/chain stay do you get the same flex?
If the flex is only apparent when grabbing the wheel, check your hub bearings.
My experience with Santa Cruz VPP rear triangles is that they are very stiff laterally when the pivots are adjusted correctly.