There is a link (assuming you linked the bundle to your account) you can view the bundle via Libraries > Purchases/Bundle > Then click the bundle.
From there at this time you can search up the game in question. There is also getting the Itch.io App but servers might be wonky and cause the download to say error instead. Thru the app you will have to go to the bundle's download page like you would in the browser.
As for other news, I think an add all button is in the works. If you can wait say give or take a few days it might appear in the bundle downloads page. This is just an estimate / guess. No telling exactly when.