Is tungsten wattage different from regular wattage?
Yes, apparently "tungsten-heater" load type is measured differently than a ideal/purely resistive load type! 

Check this for example - http://www.nkkswitches.com/pdf/electricalratings.pdf - you will see chart of the current v time "inrush" curve for tungsten filament electrical light bulbs - while cold, their resistance is very low - so they spike when switched on (not coincidently that's the time when these burn out - during power-on). 



And thus differences in ratings, for example this smart switch allows only 1/2 tungsten load than resistive: 

ELECTRICAL RATINGS
• Electrical rating: 15A, 120Vac, 60Hz
• Resistive: 1800W
• Tungsten: 960W
• Electrical Ballast: 500VA
• Type 1.B Action