Damage to the wall and pipe repairs would be classed as buildings insurance. Whether you can claim for them successfully under your building policy is another matter.
Without knowing what cover you have, I would probably say that unless the leak from the pipe has been caused by an insured peril i.e accidental damage etc (accidental damage has to be something specific happening to the pipe i.e nail going thru it or something similar rather than pipe or joint merely leaking) then the cost of pipe repair won't be covered. If the pipe is in your flat vicinity then most likely the costs involved will be down to you to meet.
Your policy may cover u for trace and access tho, which means that it will cover the costs (labour time most likely) of a plumber tracing the leak but not repairing it costs. you'd need to check your policy.
As far as water damage to your wall, you should be ok to claim for that - so long as you had no idea of leak, and this is the first you'd noticed it then wall repair should be covered
hope this helps