Police said she was working in the cellar at Vickers Street Social Club when she saw two men in the club just after 10am on Monday (June 18).
A West Yorkshire Police spokesman said: "The suspects approached her and took some money from her. An altercation occurred and the lady was assaulted causing minor injuries."
She was taken to hospital for treatment and later discharged.
The first suspect is described as a 5ft 11in to 6ft tall white man, of medium build.
He was wearing a black hoodie, with the hood up, a black baseball cap, blue slim leg jeans and dark coloured trainers with a white sole.
The second suspect is described as a 5ft 6in tall white man of stocky build.
He was wearing a dark blue hoodie, with the hood up around his face and dark coloured trousers with pockets down each leg.
Anyone with information is asked to call police on 101, quoting crime reference number 13180295057 .
Or call Crimestoppers anonymously on 0800 555 111.