Does Wind Demon card 648 cause it to attack twice if it can spend wind?
The rules say

Elemental infusions can be used to augment the effects of certain abilities.

So if wind is consumed the wind demon will perform move + 0 and Attack +1 with the greater AOE.
If it was to perform at attack again it would say Attack +X, If you look at this Cave Bear card for comparison which has two attacks.