Fancy enough for a honeymoon resort with big animals and shore diving is a very short list. Esp. if you mean on-site shore diving.
Bonaire doesn't make my big animals list except for more expensive east side diving - one operator goes out there with a RIB. Neither does Roatan - except for the paid shark/dolphin dives.
Look at Grand Cayman. The only issue there is that the two dive resorts - both on shore dives - are at best average properties. Cobalt Coast is also 20mins. drive from anything - Sunset House is in the flightpath. CC has the advantage of North Wall access where you likely will see big animals, rays, tarpon, turtles etc. Not a lot of sharks though. A good idea of what to expect:
iDive Global Locations If you stay at the resorts along Seven Mile Beach, boat operators will pick you up - just about all have a shuttle. The Westin is pretty nice. Many of the shore dives are within a 5-10min. drive of there also. Cayman is really pricey though also.
Turks and Caicos might work. There is good big animal diving off West Caicos and French Cay - a 45min. boat ride away from Provo. Lots of sharks, rays, turtles, grouper, occasional dolphin. We saw most of that on every dive at French Cay. Provo is as expensive as Grand Cayman but with even a better beach - Grace Bay is called one of the nicest beaches in the world. But you can't dive from it.
Grand Turk might be an option also, it's smaller and quieter. IIRC Bohio Dive Resort has shore access to the wall there.
How do you feel about Hawaii? Not especially exotic but some of the hotels/condos in the Kihei area in South Maui are on shore dives. The Grand Wailea - it's a big resort - is as upscale as you can afford - all the way up to concierge level floors or private villas. They also have honeymoon packages. It's on the Wailea Beach dive site - a decent shore dive - and somewhat dive focused - they have an on-site operator, teach classes etc.
It's within 5mins. drive of other dive sites at Makena Landing, 5Caves/Graves and Ulua Beach. Downside of the GW is there's a waterpark so lots of kids. Did I mention it's a big resort also. The Wailea Beach Marriott nearby is between Wailea and Ulua Beach - IDK much about it.
There's also the Sheraton Black Rock in West Maui. Nice resort, good beach, and Black Rock is a better than decent dive. There's also a resort operator on-site for tanks etc. Could be dozens to hundreds of snorkelers overhead though. It's in the heart of the real touristy part of Maui also.
I think there's a shallow dive/good snorkeling at the Four Seasons at Manele Bay on Lanai also. IDK about regular boat diving from there though.
Anse Chastenet on St. Lucia might be another option. Or Jade Mountain higher on the hill above it is even nicer. There's both beach and boat diving off the resort. IDK what big stuff is off St. Lucia but Scuba Diving voted their dive one of the Top Five shore dives in the Caribbean. There's also a big wreck they put down a few years ago nearby.
ANSE CHASTANET RESORT St Lucia, Caribbean's most romantic resort
Jade Mountain, St Lucia's Most Romantic Luxury Resort
Lastly, IDK how much shore diving they do there but this place makes my dive bucket list:
Maldives Activities | Diving | Four Seasons Resort Maldives At Landaa Giraavaru Anytime the resort webpage features a Manta you know it must be good...