The corkage fee is charged on the bottle no matter where you drink it. If you pay the fee and want to take your bottle to the dining room make sure you bring along the receipt that you paid the fee so they know that it has been paid.
Also, bring the bottle in your carry on bag. If they find it in your checked luggage, after they have called you down to open your bag, they may just hold the bottle until the end of the cruise and not allow you to pay the corkage fee.
Some have said that they were able to sneak the bottles on the ship, just make sure it isn't going to ruin your day if they call you down and you get caught.
Have you checked out the wine list at the ncl site, they have quite a collection and when you add on the $15 corkage fee to your own bottle it's almost not worth it to lug it on the ship with you. You can purchase the wine with dinner and take the remainder of the bottle back to your cabin to enjoy later.