Qantas appear to give extra status credits (their equivalent of tier points) in the Qantas Frequent Flyer programme when booking an extra seat on a Qantas flight.

https://www.australianfrequentflyer....comfort-seats/

I suppose in a roundabout way when you buy a Club Europe fare you are paying extra for the seat next to you to be unoccupied (other than sometimes by a table) and you get extra tier points.