can I pool miles from family members and book tickets on NON-Asiana Airlines?

or is it only for Asiana flights? How about codeshare flights?

I know for Korean Air Skypass, you can't redeem family miles for other airlines. Only for Korean Air I believe

Does anyone know if the same holds true for Asiana? (I don't know if they're still doing fuel surcharges but would like to avoid those and also have more flexibilty with places to travel that might not be in Asiana's network)

We live in SF and use United a lot, so typically credit miles to them.

But I was thinking this would allow my family of 4 to have more flexibility to pool our miles together.

Thanks!