Just to refresh this thread folks; two questions:

(1) Do you have to book the 'full' fare within a particular range of booking classes when booking a companion fare alongside? For example, can a deal/sale fare be booked in a cabin, with the companion then purchased alongside? Obviously, rules state that you can't upgrade to a cabin, then purchase a companion fare, but there appears to be no rules around which fare you purchase, provided it is straight into the chosen cabin?

(2) Are you limited to one companion only, or can 'companion' extend up to yourself and 2-3 others, for example, when travelling with family?