You’re allowed to play one time each day for the time period for either 1 week, 2 weeks, or a full month depending on your last transaction date and point amount.
Here are the terms again for reference: To unlock Scratch & Win, you must have at least one 100 point transaction within the last two weeks. If you have such a transaction, the game will be unlocked and available to play for 1 week. If you have a 500 point transaction within the last two weeks, the game will be unlocked for 2 weeks. If you have a transaction worth 1000 points within the last two weeks, the game will be unlocked for a whole entire month!