I would also like to know how to do this. I imported a STEP file and patterned it. Now I want to rotate it. I like how in AutoCAD you just type rotate and it does what you tell it to. I wish Inventor were as intuitive as AutoCAD.
I ended removing the pattern. I rotated the original part using grip snap and then redid the pattern selecting the column direction on the angle I wanted. Still I wish it was as easy as AutoCAD. In AutoCAD you don't have to backtrack as much because all commands are available to you all the time.