After bottoming out a year ago, Las Vegas home values have soared and are expected to rise further, boosting the region’s fragile economic recovery. The Las Vegas Valley’s median home value was $138,800 as of March 31, at the end of the first quarter, up 22.3 percent from a year earlier, according to a report out Wednesday from Seattle-based research firm Zillow. Local home values hit bottom in the first quarter last year at $113,500.