The new Elrond and Vilya text allow you to reveal the top card of your deck and put it into play if able. Can you use this ability to put Allies into play for Spheres that you do not have a hero for? Elrond's text allows you to use his resources to pay for allies from any Sphere, but the rules also state that to play a card you must have a hero with that Sphere. One could also argue that Vilya's text isn't playing the card, its putting it into play.

Very interesting card combination. Eagerly awaiting the answer to this.

You are correct that put into play is different from play a card. Since Elrond and Vilya let you put into play a card, it does not require a resource match. So it is perfectly legal.