Do I have access to create Power Audiences?

To determine whether or not you have access to create Power Audiences, click the Power Audiences tab:

Now that you're in Power Audiences, look to the top right of your screen. You should see something similar to this:

If you have a Create New Power Audience button, then you have been granted access to create Power Audiences.

If you don't see this button, the only access you have is to create a segment based on a Power Audience.