If you go down the links: Forums => models Vstar at the top is the sticky threads
and the last one is mileage threads
there is one for the 1100.. Looks like average on the main tank is 120 to 140 miles
some things that would affect mileage: is the bike stock, or does it have modified exhaust and mods to the fuel system?
Also you might have been running old gas, put four ounces of sea foam into 4 gallons of gas in the tank, and see if it improves.
There are other suggestions for improving mileage in the thread mentioned above.