So I got a Wink for free when I ordered some Quirky stuff. I’m not using it currently but I’m in need of a Zigbee repeater. Anyway I could join the Wink to my ST network and use it as a repeater?
Short answer: No.
Some of the wink hubs are rootable, but this has been patched with a firmware update. I have seen reports that you can add the wink hub as a secondary controller to a z-wave network, but nothing on zigbee. With the device being rooted, It might be possible to get it to act as a zigbee repeater. That is just way too much work when there are plenty of off the shelf devices that are guaranteed to to give you a repeater.