If you look at some RL examples, the common Pterosaurus didn\'t have much of a tail, due to the structure of its limbs (
see here). Other smaller types, such as Rhamphorhynchus or Dimorphodon, generally had long spaded tails (
as seen here).
The difference between these creatures is that the smaller reptiles had evolved for fast, maneuverable flight, whereas big Pterosaurs were \'gliders\'; some scientists theorise that they couldn\'t actually \"fly\" at all. These would have been slow and unable to change direction quickly like the little ones.
Because of the structure of your Pterosaur, i.e. wings attatched to the body rather than the legs, it needs to follow suit with the smaller reptiles, but the tail will need to be slightly larger than proportionate size, due to the fact that it needs to be able to support passenger(s) and cargo.
The wing muscles should be very defined aswell. The limited span means it will need to work extra hard to even take off into the air fully loaded. His arms currently look like sticks... easily snapped.

Here\'s a good comparison between wing structures of various creatures, including a Pterosaur:
http://www.transitionrig.com/wings.htm[Edit: Found a better Pterosaurus pic]