Phil:
My "new bride" and I were married in May and did almost exactly as you and your bride-to-be would like to do. We went to Elbow Cay, which is a small island only 3 miles long that's due east of of Abaco, the largest and 2nd most northern Bahamian island after Walker's Cay.
We rented a private home 200 yards from a private beach that looks exactly like "Gilligan's Island". There were bones on that beach on the incoming tide and I cast to 2 permit there as well. There's plenty to do on this island or neighboring ones, especially for honeymooners.
Home rentals go from $750 to $1100 for 9-10 days. Airfare for 2 from Boston was $870 direct from Logan to Florida and another ~$300 round-trip for 2 from Florida to Abaco.
There are ferries that go throughout the island chain for $5 to $8 each. The guides in this particular area were few, but I did hook up with one, learned where to go and what to do, and then rented a 17' Whaler for ~$400 for 8 days of fishing/swimming, etc.
Check out the web and do a search on "Bahamas" or wherever you're interested. The only drawback to the 10 days we spent was that the winds were howling around 20mph plus. While I could cast OK, it was tough to see fish. But - I'd do it again . . . including the marriage part!
Good luck! If I can offer any other assistance or info - email me. Dale