they can always try it. Dodge Jeep and Chrysler shares the same key except the logo, as mentioned. The dodge parts catalog have cross reference on keys with different logo.
HOWEVER, even if the key looks the same, they are NOT all the same. Let say a key for a 05 minivan will not work for a 07 minivan, even tho they look exactly the same.
Do you have the Part number off the key you bought from ebay? maybe some of us can look it up for you and see if it works for ur vehicle.
tizzy is right, buying keys fobik off ebay is tricky.