Can you link multiple asset purchase bills to one asset in FAM?

We do this through Manage Asset Proposal page. You can edit the Asset Proposals and select a Parent. Only the parent proposal will show up in the Manage Asset Proposal page. It will create a single Asset record whose values are the total of the parent itself and its children (based on the Asset Proposals).

Thank you Luis, I suppose new bills could be added after initial asset has been proposed too?

I'm sorry, you meant an Asset record is already created and you want to create new Bills and add that to the existing Asset record?

Yes

I'm not sure about the best practice but we were told that the only way to do that is to create a Revaluation transaction for the existing Asset record and reject the Asset Proposal of the new Vendor Bills, so that they won't create a new Asset record. This is under the assumption that there should be only one Asset record (parent-child relationship and component asset wouldn't work). 'Cause there's no native functionality to do it