We have a Landry's card and in our experience, including 2 weeks ago, is that all you have to do is show up at Y&Y and show them your card and they'll find you a table. Sometimes you have to wait a bit--rarely more than 20 minutes or so--but they give priority to Landry's card holders.
And, yes, ADRs are quite hard to get right now. If you have the time, what worked for us was basically stalking the WDW reservations site. We were able to fill in all the places we wanted to eat. And, of course, the 24 hours before is a great time to look for rezzies, since that's when a lot of people cancel.