I think if you are booked under LA code (theoretically), you should receive mileage as if you were on LA metal flights (segments and km counting according to LA flight terms and conditions).

I am still waiting for my LA coded IB flight to post (my sixth mid/long haul segment on LA and LA codeshare to qualify for lower Comodoro km requirement), but it hasn't posted (10 days since my flight), while my IB coded flight MAD-GVA posted yesterday.

The flight in question is SCL-MAD, booked/sold as LA code but flown on IB metal.