Hotel discounts are only provided if the bride and groom set up what's called a "room block"you will know whether they've done this if you get information from them about certain Disney hotels that they encourage you to book. If they're having what's known as an Escape Wedding (23 guests or less is a good indication of this), chances are they will not be setting up a room block, so there will be no discounts.
The wedding discount rates are based on time of year, but you can usually figure on about 30% off at Deluxe resorts that have a convention center, 15% off at other Deluxe Resorts, just under 15% off at Moderates, and less than 10% off of Values.
You may find that there are other lodging discounts available to you that are more advantageous. Sometimes the offers to the general public are better. So if you don't book your room using the special wedding discount hotline, it will be REALLY helpful to the bride and groom if you give them your reservation number so it can be manually added to the block of rooms they may be required to set up.
The wedding discount on tickets is available to all wedding types; it's a flat $20 off any park hopper ticket.