Bonding sub panel

I inspected a house with a subpanel. The feeds from the main panel come off of a double pole 60amp breaker. I did not find a bond in the main panel, but the subpanel is bonded. I know the sub panel should not be bonded if the main panel is bonded, but since the main is not bonded, is this configuration OK?

Bonded to what?

The sub panel must be bonded to the service panel.

The equipment grounding conductors (egc’s) must be bonded to (and at) each panel.

The neutrals must be bonded to (and at) the service panel.

The neutrals must not be grounded at, nor bonded to the sub panel.

The sub panel must be bonded to the service panel. It appears to be bonded with conduit from main panel to the sub panel

The equipment grounding conductors (egc’s) must be bonded to (and at) each panel. This is present in both panels.

The neutrals must be bonded to (and at) the service panel. NOPE-did not see it present.

The neutrals must not be grounded at, nor bonded to the sub panel. YES, as seen in the picture, the green screw. Maybe I should have said bonding screw or strap.

The sub panel wiring is improper. The bonding screw needs to be removed, and the egc’s should be removed from the neutral bus, and attached to the (empty) grounding bus, which is bonded to the enclosure as required.

There must be a bonding screw/strap/conductor at the service equipment that bonds both the egc’s and the neutrals to the service panel enclosure.

The bonding between panels (via conduit) is acceptable, depending on the code-cycle your area follows.

The panels have obviously been installed and/or modified by “less than a professional.” The service panel is also being used as a raceway, which can be indicative of non-professional workmanship.

Thanks, Jeff. As always, you have the answers!! The question answer format was very helpful.