Are you sure it doesn't show? Remember that you have to first manually find the game in and download it from the 25 48 pages of the bundle (page 21 according to others) before it will show as registered to your account on the game's individual webpage.
Viewing post in Bundle not showing up in library
yes exactly, that's the issue. unless you do that it tells you to buy games you already have.
since the store page already shows you the bundle (and asks you to also buy that again) they just need to add a "does the user have this bundle" check in addition to the failing "is it in their library" one.