I think it won't be limited to TA members. If it is, that won't be very fair.
I'm guessing they'll be using the same plan as what they did to give out the special RnRC Tour postcards last time. At the end of the concert, you can access a special site with your mobile, and on the site will be listed the "lucky" seat numbers who won. Those people just had to bring their ticket over to the redemption counter to get their postcard/backstage pass. So you don't need to be a member, as long as you went for the concert and have a ticket, you can take part.
