From the new Global Link event Eeveelutions?
I like Vaporeon with Hydration and Glaceon with Ice Body.
Wish / Yawn / Substitute
I'm going to say... neither. Go with Espeon! That ability is incredible! All non-attacking moves used on Espeon will bounce back and affect the foe. This even includes entry hazard moves, so switch it in at the start and your opponent will probably have used Stealth Rock only to have it bounce back!
The two you have up there are either outclassed by others (in the case of Vaporeon. Vaporeon needs Water Absorb) or it is just worse (Glaceon prefers not being hit to a tiny bit of health)
I would probably go with Glaceon. It can learn a variety of moves and mine dominates with special attack.