Thanks for asking! If you have the digital version of Gears Tactics then it is a Xbox Play Anywhere title, which means you can play it on both Xbox and Windows 10 PC.
Hit trade value at top, under pictures/videos of game, it tells you cash value and store credit value, for pros or not. Currently its 11$ cash 13$ store credit depending if your pro or not.
I got the bundle and it came with the digital copy not a physical disc
Yes you can