eCogra has criteria which can be found here: eCommerce and Online Gaming Regulation and Assurance – Reputable Portals Seal – Criteria
The basic rules are:
Six Months in Business
No Black Hat SEO
No Spamming / Unethical Activities
Don’t promote known “Rogue Operations”
You can also apply for a CAP Affiliate Portal Seal here: CAP Trusted Affiliate Portals, Websites, Directories & Blogs
Hope this helps.