Do you mean purchasing BT Sports via NOW themselves or is the BT Sports App on NOW branded playback devices ?
Republic of Ireland NOW customers can purchase an optional NOW Sports Membership with the BT Sports channels on them, where us customers based in the UK need to buy the monthly BT Sports Pass directly via BT Sports.
With regards to the BT Sports App, this App is available on both the NOW Boxes or NOW Stick.
Apologies, I could have said more. No, BT Sport is not available via NOW TV. But you can get it by subscribing on a monthly basis directly via BT using their app which is available on a wide variety of devices.