Select Shapes (Vertically Align Center)
1. Start by Selecting the 2 shapes you wish to align. I would start with the shapes on the opposite sides first. You will see Align Tools in the Control Panel and the Align Panel.
Check what you are Aligning To
2. Before clicking the Align Tool always check what you are aligning to. The tendency is it is always the opposite of what you want. We will be Aligning to Selection first.
3. Group the objects you just aligned on the far sides. The objects will collapse if you forget this step. You only need to group the far side objects not anything in the middle.
Align to Artboard (Vertically Align Center)
4. Select All – Now select everything on that layer or the groups you wish to be aligned in the middle of the artboard. Double check you have aligned to artboard selected.