From Hawaiian's website:

Visa Signature cardholders will receive 20,000 Bonus HawaiianMiles after first purchase and 2,000 anniversary bonus miles each year when their account is renewed. Visa Signature cardholders will also receive an additional 15,000 Bonus HawaiianMiles after making $1,000 in net purchases that post to the account within four months (120 days) of the account open date. Platinum cardholders will receive 10,000 HawaiianMiles after first purchase and 1,000 anniversary bonus miles each year when the account is renewed. All miles earned with the card are awarded to the HawaiianMiles account of the primary cardholder. Please allow approximately four to six weeks for miles to be credited after qualifying.


Only you can decide if the card is worth it to you. Do you want to have another credit card? Do you want to have a card with a $79 annual fee? If you don't have any other card earning miles/points/cash back, then I would definitely recommend getting one that works best for you. I have had the Hawaiian card for 9 years now but will be cancelling this year before my fee hits my account because I prefer a different card now as my needs have changed. Do you fly Delta or Continental often? They are partners with Hawaiian so maybe it makes more sense to get one of their cards. Hard to say without knowing all your details/interests.