Subscription sharing, Donation seperate.

Patron A has a subscription for two which consists of Patron B and herself. Both write seperate checks for their halves of the subscription & on top of that give a donation. They want the subscription part of this transaction ALL under Patron A's account, and want the donation part to be seperate & credited to who exactly wrote the check (understandably).

I understand a record for Patron B will need to be created, but on top of that, what other information is recorded in their record & the subscription holders record?

What are the steps everyone takes to make sure that both patrons would be searchable in the constituent screen, cross-referenceable (not a real word, i know), & clear that they are together in the subscription sense yet seperate for the donation part?

What do you all utilize in Tessitura (associations, alias, addresses, etc.) to reflect this? To my understanding associations cannot be searchable in the constituent search screen.

PS. Donations with subscriptions are processed through the box office & generated by Development.

Thank you.