By work, I presume you mean if could it generate a profit. To that, the market seems pretty lean. The Spokane County US Census data has Spokane county just over 470,000 people, with the latino population reported at approximately 21,000. My math may be rusty, but that's 4% of the population. Hispanics are a little over double the african-american and Asian populations if these numbers are accurate.
Meanwhile, the "white" category includes 420,000 in it's reporting. That jives with my impressions around town. Spokane is very white. Hispanics haven't yet moved into the area in the quantities that Yakima County, Tri-Cities or Puget Sound have seen.
As to a profitable spanish language station in Spokane? I just don't see the revenue in the market - yet.
Brokered, maybe with some of the other languages that are prevalent in the community. Full on Spanish ala KZHR/Walla Walla though, Not here, not yet.