Congrats on the engagement! I would go with option A because by the time you have your honeymoon you will most likely have racked up many, many miles which will most likely give you and your fiance round trip tickets. I would say the hardest part is picking the proper card with the proper airline. This is why you might try going with a general rewards card that gives miles for many airlines rather than just one. Some cards that do this:USBank Flexperks Travel Rewards Visa Signature Card
It doesn't appear that this card is too common, but I think the rewards it offers are excellent. Just 20,000 Flexperks = $400 worth of airline credit. 30,000 Flexperks = $600 worth of airline credit, etc. Not only this but you get a $25 airline allowance with each reward ticket. This means you get reimbursed for things baggage fees or in-flight purchases. The card comes with a EMV chip, so you won't have to specially request one. The other good thing is, Flexperks can be used for mostly anything (note the 'Flex' part). Gift cards, airline tickets, hotels, electronics, clothing, and even statement credit! Even after your honeymoon this could be a beneficial card to you. With the current sign-up bonus, you get 20,000 Flexperks after you spend $3,500. I don't think this has a time limit, but I'm not positive. You get a FP per dollar spent, and double FP's on the category you spend the most in each month. Additionally, you gain 3,500 bonus FP's each year you spend $24,000 annually. There is a $49 annual fee. I would say that the major downside to this card is the fact that the website looks like it was constructed decades ago, and therefore is very plain and harder to navigate. I think what 'sells' this card is the point to dollar/mile conversion. Also, you get visa signature services and travel accident insurance. There are even more benefits!United MileagePlus Explorer Card
This is a card offered from Chase. It gives the signup bonus of most airline CC's, and that is 30,000 miles after spending $1,000 in 3 months. You get a additional 10,000 bonus miles each calendar year you spend at least $25,000 on the card. The first checked bag is free for the primary card holder, as well as the companion on the same reservation. There's no foreign transaction fee. You can earn a bonus 5,000 miles after you make your first card purchase and add an authorized user to the account. Unfortunately, I am not sure of what the point to dollar conversion is, but I would assume 30,000 miles is somewhere around $400. United Airlines flys nearly everywhere, so this would be a good card if you want a specific airline card. $95 Annual Fee.
There are additional cards you might try exploring such as the Chase Sapphire and American Express SPG. Hope this helps!