Does going faster always result in more calories burnt Say the same 5mile ride going at 5 miles per hour versus 10, 15 20 etc.  Even though the faster speed means shorter ride does it also always result in more calories burned?
I have the same commute looking to up the exercise somehow.
All other things being equal, yes. The increase in effort more than makes up for the decrease in ride time.
Consider two scenarios where one rides 20 km: first at 25 km/h, second at 30 km/h. In the first case, riding at 25 km/h takes 96 W of power, in the second, riding at 30 km/h takes 150 W according to this web page (using my own stats).
 96 W * 20 km / 25 km/h = 276 kJ over 48 minutes  
150 W * 20 km / 30 km/h = 360 kJ over 40 minutes

Thanks to a lucky mathematical coincidence, kilojoules of work is almost exactly equal to calories burned. Some estimating tools treat calories burned as 10% above kJ of work.