I have no axe to grind in this dispute mainly because I have no idea whats really going on between BASSA and BA. However the staff travel issue is below the belt, uncalled for and my money is on it biting BA back very hard.
Again you should be careful what you wish for. This tactic has serious implications for everyone if not very quickly beaten back down.
If this were a dispute like previous disputes where management offer a pay deal of x%, union proposes y%, strike ensues, then many may agree with you that withdrawal of staff travel is below the belt.
However, I think many would argue that this is no ordinary industrial dispute it is the behaviour of BASSA that has been well and truly below the belt.
The industrial action started in response to BA changing the crewing levels on aircraft to achieve costs savings after no less than 9 months of negotiations with BASSA during which (as documented in a High Court judgment) BASSA refused to sit in the same room as the reps from CC89 and there were, in the words of the High Court judge, "heated arguments" between the two factions. Also, the largest accountancy firm in the world found that BASSA's own cost-saving proposals were not even one third of what they claimed.
Many would argue that BASSA's behaviour has been wholly unwarranted and massively disproportionate - not least because the "imposition" that prompted the strike was a direct consequence of its own failings. There can be no clearer evidence of this than the massive response of BA's own unionised workforce to mitigate the impact of the strikes. Has there ever been an industrial dispute where the strikers have been undermined by their own fellow unionised colleagues?
So let's put this another way, if a group of workers inflicts £150m+ of damage to a company which makes changes found by a High Court to be perfectly reasonable when in the teeth of one of the biggest crises in aviation and the near meltdown of the global financial system, should that company continue to provide that group of workers with a generous non-contractual perk?