When you rotate an object in illustrator the transform controls to resize it/squash it rotate with it. What if i want to stretch it relative to the canvas?
I think you want to reset the bounding box so it aligns again with canvas properly.
You can find this command by selecting the artwork and then rightclick>_Transform_>"Reset Bounding Box".
this will realign the transform controls as they were before the transformations
Use the Free Transform tool. Either select free transform from the palette tools or press E on your keyboard, a bounding box will appear around your object. Use the anchors to stretch your object, hold alt+shift to have it stretch and keep its ratios :)