Programming files are speed grade independent, and you will be able to configure devices of different speed grades with the same file. Please note you may have timing issues involved when doing this. You should choose the device settings in Quartus® II software that match the speed grade marked on the device.
You may experience timing problems if targeting the place-and-route to a fast device and then download to a slower device. You should not have problems targeting a slow device and then running it on a faster device unless a minimum timing path is faster than the design can tolerate.