Grounding and bonding are not the same thing, although they are related. Grounding means connecting things to ground through a single grounding point in the area of the main panel. Bonding means connecting everything together, without regard for the ground.
The bonding system should not be connected directly to ground, though there may very well be an indirect connection through the pump or a lighting circuit. Driving a grounding spike is not recommended in the US, though some other countries recommend it.
There should be two different connections on the pump. One by the motor next to the AC input that gets connected to ground and another on the pump housing that gets connected to the bonding system.
If the pump doesn't have two connections what would be correct, to bond in the same lug as the ground or create a bonding point thru a housing screw?