well, it depends.
in my case, 1 principal + 2 supplementary. all separate statement. All 3 person has their own individual PIB account, so each card is linked ("add card") to each PIB account. Once this is done, too late.
*** currently i'm checking all 3 PIB accounts to check outstanding, transaction history, etc.

***
there is a user here, 1 principal + 1 new supplementary. all separate statement. Principal requested branch to add supplementary card to principal's PIB (i.e. 1 principal PIB = 2 cards). he managed to get this done.
If i get the sequence correctly (nobody knows what is the actual process), as long as supp card has not been "linked" to any PIB, then you can do this.
in my case, my supp card already been "linked" to its own PIB account, i cannot unlink it already.
i'm planning to get another supp card, this person doesnt have PIB account. I might wanna try to link the card to my own PIB account. let's see how it goes, if i applied it

i think depend on the branch. i went to 1 recently and told me cant coz is separate statement and each have own limit. if combine limit then can. my supp do not have pb account at all.
maybe OUG branch have different protocol since able to do at there.