S.H.
I can't think of any Marriots or Omni Hotels near there. (I am from San Antonio.) I don't know how much time you're planning to spend at Sea World, but if you're going to spend more than a day there, you may consider just buying the Season Pass, which is about the price of two days. Plus, Sea World is open longer throughout the year now; so, if you get the pass, you'll be able to visit again...maybe for Halloween? :)
Anyway, it also depends where else you want to visit, how much time you plan to spend in the hotel, and what amenities are important to you about the hotel. I can think of a few nice ones around there, if you'd like any recommendations. Let me know! :)