Some WishList Member customers are currently using systems like Clickbank.com or 1ShoppingCart.com to manage their affiliates so it is possible to setup a membership site using WishList Member and have an affiliate program at the same time.
Essentially, it would work just like any other product that you would setup with these programs. You would use the URL of your membership site as the product URL and then any person that is sent to your site through an affiliate link will automatically be cookied. So if they purchase, the affiliate will be credited accordingly.
That being said, we do have an integration with iDev that you can check out.
Information on this option is located in the Other Resources section of the Customer Center. Instructions and a download link are also included.
//customers.wishlistproducts.com/other-resources/ (must be logged in the Customer Center to access).