Although many employers review pay on a regular basis, unless there is an express contractual entitlement or implied right (i.e. entitlement by virtue of custom and practice), there may be no obligation on the employer to do so.
There may be a collective agreement between the employer and the union, which includes provision for, say, an annual review for certain grades of worker. However, unless the agreement says otherwise, or you can show that the carrying out of a review has always led to a pay increase, this would only commit the parties to meet for negotiations, which would not necessarily result in an increase in pay.
