Here's an e-mail content from Google Adsense:
"We've recently updated our gambling content policies for publishers in selected countries where gambling is legal. Publishers in these countries can now apply to monetise their online gambling content. Permitted gambling content includes: online casino games, sports betting, bingo, lotteries, tips, odds, handicapping, mahjong, educational/supplemental materials and bonus codes."
You can visit AdSense gambling policy page for more details on this new policy and contact them if you’re interested in monetising your gambling content.