There was no probationary period for the PRIV benefits I got with the First Group TOC I work for. Dependant children (in full time education/under 16 plus a couple of other circumstances) generally get their own pass as well on top of your main nominee. I think you may be able to nominate someone else to use the pass - I don't think it necessarily has to be partner/spouse etc but i'm not sure.Re the free travel for you and spouse that most TOCs offer, is this offered from day one, ie from when you start training? And if you do not have a current 'spouse', can you give it to a close family member, such as Daughter or Mother?
ATOC would be the people to tell you for definite, though it wouldn't stop me applying if I wanted the job - benefits or not!