I have to admit - though I love the Poly and the two restaurants (and the counter service), none of them are very romantic spots. The food is good at both though.
Here is why I think that. Kona Cafe - very loud; acoustics are sooo bad - you are close to other tables. Lovely dinner - wonderful desserts, but not really romantic! Now we have eaten there four times so you can see that we enjoy it!
'Ohana - again. Food was good, but it is a theme with coconut races and some entertainment (if you can call it that

- ukelele and all!). Anyway -- lots of fun -- again the food was good ... but not romantic.
Counter service is never romantic so I won't address Captain Cooks for that!
Would you consider ROOM SERVICE (if you are staying at the Poly)??? I have looked at the menu and you have the best food from both restaurants available. There is a fee but I don't think that bad.
If that is out of the question, eat at either of the TS in the Poly and then relax on the beach and watch Wishes (bring a sweater - even cuddling can't keep out all the cold!).

now
THAT is definately romantic!