BTW, you can test it. Open the hood and put the car in drive and power brake until you get boost and release. Have someone stand to the side of the vehicle and watch for the big plunger to open up (or you might hear it).
If you don't have a second person figure a way to video with your phone and look for it.
The only thing else I can think of is there's a check valve in that line you tapped, I used it for my Flex but it was a 2011. Hook up a cheap vacuum gauge and verify you're building boost and then vacuum on that line. You can pick up a cheap vacuum/boost tester for like $15 at AutoZone.