I think your best bet for 'romantic' and 'great steak' would be Jiko. It's low lighting, very quiet, the back wall changes color throughout the course of the evening to represent an African sunset, and it overlooks some beautiful plants and waterfalls. They have a great wine list, and their oak grilled filet is to DIE for.
The CA Grill is my most favorite restaurant on property, but I wouldn't call it romantic. Yes, there is a great view of Wishes if you time it right, but it's always VERY busy and VERY loud. Excellent food, though, so would be a good choice regardless. Narcoosees is very romantic, and also has a wonderful, if different, view of Wishes, if you think you'd like to see the fireworks with dinner - they pipe in the music as well. However, I can't remember how great their steak is.
So, I vote for Jiko - it meets both your requirements!