Spectromagic (and also daytime parades) have several handicapped viewing areas. There are no special spots for Wishes - since the fireworks are in the air, they idea is that you will be able to look up to see them.
One parade viewing area is in the hub in front of the Train Station on Main Street. Just be aware that area can become quite busy after the parade with people trying to leave the park. You can watch Wishes from that end of Main Street, but it will be in the distance.
There is another parade viewing area in Liberty Square near Liberty Tree Tavern. If you stay there for Wishes, you will have a very obstructed view.
The last parade area is in the hub by Cinderella's Castle near the walkways that go toward Tomorrowland. You could stay in that area for Wishes, but it will be very congested because many people congregate in that area for Wishes.
One good spot we have used for Wishes is the walkway sort of in front of Crystal Palace. There is a grassy area with a fence that you can park right in front of. THat way, you won't have anyone standing right in front of you.