Here its the example updated
https://copy.com/lPxgSVUjsU3Q
The wind now can blow left or right, and the bullet is affected properly.
if you want it to blow in 360 directions you only need to make the wind affect the gravity of the bullet the same way it is affecting the power.
<img src="smileys/smiley1.gif" border="0" align="middle">
You can also try with physics, like Guizmus propossed. Look at a couple tutorials and once you know how to use the physics beahvior you will be able to make a much nicer simulation.