we stand on the bridge to the right of the castle that goes into tomorrowland and she flew right over our heads, we could see her face so good, it was the coolest!
You might not want to be TOO close with little ones. It could spoil the magic. Last trip, we were standing near Tomorrowland Terrace. As Tink flew right over our heads, a teenager proclaimed loudly, "Hey... that's a DUDE!"
I also agree with the Tomorrowland bridge, that's where we usually watch.
If you are going to be there while they are still doing the Memories projection show (15 min. prior to Wishes), you may want to be on the part of the bridge closer to the hub. We were there on 9/18 and Tink flew directly over us, but we couldn't see the photos projected on the front of the castle. We could still see most of the castle projections though, and the show was so cool!