Hey Pat,
It doesn’t look like it’s related to your affiliate account at all.
I think it’s about your Grand Mondial players account, so you should probably contact the casino. Maybe you need to update information on your players account. It’s not like we can see what’s on our players account profile stuff. So maybe they noticed something that raised a flag and you just need to update them.
I don’t think it’s a big deal. Just send them what they’re asking which basically is to identify you. I had to do this at Grand Mondial earlier this year when I cashed out. They had my account as a linked account. I haven’t the slightest idea why… but I sent them what they asked for and it was released just that easy. And I had my $20k cashout in 24 hours from the time I requested it. 
Grand Mondial is good.. don’t worry.