Mostly Meh, maybe.
Some VW years had rear suspension stops that had a stud and were essentially bolted onto the shock tower. Other (later?) years had a similar-looking bumper, but it was somehow glued on to that mounting position. It was pretty good glue, otherwise they could fall off after bottoming out a few times from having three fat friends with you.
If the mounting spot for your bumper has no hole and you wish to use the studded bumper you could just drill a suitable hole where they mount and put them in. You can get great access from below.
If you glue them in I would use something like Locktite Power Grab to really hold them on.
Just remember that with a lowered car, such as you have, adding the rear bumpers will give you about 2" - 3" less downward suspension travel. If that's OK for you, then go for it. Peek up in there and see how much room you have with the car at rest, either on a drive-on lift or with jack stands under the shock mounts, rather than the frame, to get the suspension to settle at "neutral".
Just FYI, I haven't had rear suspension bumpers on Pearl since day one.