Fares are going up regardless of whether staff get a pay rise or not, just like they always have.
They will go up, but will it be by RPI, RPI-1, RPI+1? Who knows. That increment has always varied over the years, depending on how generous the government of the day was feeling.
What’s the benefit of not having new members join the pension scheme for 2 years?
That the company has no open ended liability for those who leave within the first 2 years, which for some roles is a lot of people. And with each TOC (presumably) counting separately you'll restart the clock if you move TOCs.
It also serves as an incentive to stay, a long service bonus of sorts. To be honest, for low to lower medium earners (say up to £30k or so), the 1.5x state pension deduction means it's actually not as attractive as it's made out to sound. But for upper medium to high earners it's a very generous scheme.
You will benefit for additional 3 years of contributions !
Yes, but that's not much use if you have already reached the maximum 40 years' contributions before you turn 65! That said I don't think many people will be affected by that particular issue.
The bigger issue is that it means you're likely to get back a lot less in terms of your pension in the future. With most sections of the RPS being in a healthy position AFAIK, this looks like a cost-cutting measure dressed up as "the horrible Pensions Regulator
forcing us to do this".