If you are using Linked Clones, we will continue to provision on the same datastore as the parent VM until the Red Space Threshold is violated. After that we will do one of 2 things.
1. make a shadow VM on the datastore in the profile with the least amount of Provisioned VMDK space. (5.5.x and forward)
2. make a shadow VM on the datastore in the profile with the most amount of free capacity. (5.1.x and back)
After initial placement, as long as all VMDK files are on the same datastore and the Vm is inside the correct storage profile/class ... you can storage vMotion the VM around within the correct storage class/profile