EA Play Membership can be purchased both through Steam and Origin.

Note that if you purchase EA Play Membership through Steam, you will be able to launch only Origin games that are available on Steam and vice versa.

For example, Boosteroid has the Origin version of Need for Speed: Heat and you can launch that game with EA Play Membership purchased through Origin.

If you purchase EA Play Membership through Steam, you won't be able to launch that game through Boosteroid since we don't have the Steam version of the game.