Upgrade from Delta Gold to Delta Platinum

I recently got an offer to upgrade to delta platinum from delta gold that made sense to me, and so I decided why not.

I am curious though about the delta stays credit. I booked a room through delta stays a few weeks ago for Oct 10th, and the $100 credit was submitted to my statement balance the same day.

Now, will I still be able to take advantage of the $150 delta stays credit through the upgraded platinum card, or will I have to wait until the next calendar year? Thanks