I'll have a stab at this
VS losses worsen considerably as the set up costs and running costs of their domestic operations hit, while they await for the DL tie up and the benefits of this to materialise.
VS continue to market aggressively with very good TV advertising.
Even with the DL tie-up and domestic services, VS do too little, too late and fail to compete effectively with the giant IAG operation and its inherent economies of scale and network advantages.
VS muddle along as best they can, screwed by high costs and route network limitations, thanking their lucky stars for DL and rightly glad of their strong brand which punches above its weight.
Thought: find a way to get under the same roof at LHR as DL, Skyteam and their new domestic flights, even if it means expanding Terminal 4 and building new Clubhouse etc. (assuming they join Skyteam)