Working from Home vs. Home-Based - rights?

[FaceLikeASlappedArse1985]

My role is managerial in the NHS (non-clinical and I don't manage staff/team)

Was 100% office-based until before Covid and been working from home since. During the pandemic the purpose of our office was changed to a hot desking space and not dedicated for our team/department - we are able to go in if we wish however this tends to be 1-2 days per person per month when we need to attend face-to-face meetings (which have only been stood back up in the last couple of months or so). We're no longer being told by the Trust to stay at home but nor have they encouraged us to start coming back in and 90+% of my work is still online

My issue is that as per my contract my base is still the office - this means that I can't claim tax allowance for working at home, nor can I can claim expenses for any travelling that I do do as the office is the furthest area of the patch we cover from where I live (I know the tax rebate plus maybe 50 miles petrol a month doesn't add up to a lot but every little helps). Friends in other NHS organisations have had their bases amended to be home-based but our Trust refuses to

Are they in the wrong here or am I?