If you placed first or second in a Weekly League, the reward will be added to your Artist account as Bonus Love within 48 hours of the League ending - no later than Wednesday. You'll also receive an email detailing the results of the last week's Weekly League group you were in.
Note that there won't be a payout to winners of Leagues where no Trophies have been earned during the week. See also: Help Article: "Will I get Bonus Love by winning a League without streaming?".