Yes you can call and have the bookings linked.
For the purpose of managing your booking, it will be invisible to you. They will still be seperate bookings and you won't see linked passengers on each others bookings or be able to do seat selection within the same view etc.
It only really makes a difference for check-in and at the airport. The airline will know you are travelling together which might help if there are disruptions. When you check-in using the app or website, you'll also see and be able to check-in all linked passengers. If your flight is subject to the group boarding process currently being trialled, all linked passengers should be in the same boarding group too.