COIN Premium is a general term for Plus, Pro, or Master subscribers. You may see your receipt say you purchased "COIN Premium" for any of these subscription plans.
You can tell which Subscription you purchased by the price of the subscription, or the subscription stated in the online COIN Account Tool, https://my.coinapp.co/.
COIN Plus is currently $24.95 a month.
COIN Pro is currently $34.94 a month.