I think Delta wants to know how much "free press" you will give the SkyWish Program. Maybe they want a link on your website to direct your donors to SkyWish site. Maybe they want you to mention SkyWish in your printed materials.
Definately look at the SkyWish listed charities and see if SkyWish Program is mentioned on those NPO websites then decide the value to your organization. If you see Delta plastered everywhere, perhaps the value isn't there. Being in the NPO world myself, its a battle not to prostitute yourself (not literally) to donors! Good Luck!