I posted about this some time ago. Steam on linux works almost the same as steam on windows. I’ll find it for you.
This bit in particular.
eveonline://callback?client_id=eveLauncherTQ&code=blahsecretblah&state=md5sum&remember=true
you need to run the launcher with this as an argument in the same wine prefix as an already running launcher in order for an account to ‘load’
That does not impact the ‘referrer’ bonus SP as far as I know though.
Before my post, I think most people were just creating a username for their steam account and logging on with the launcher directly.