And also, it would be essential to consider the policy and management style of your boss towards management-union relations.
Are you having a cordial relationship with the union or do you have fights every day?
You may please give some briefing about the management structure, union structure, your company's present style of handling the union, frequency of negotiations with the union, etc.
You may also read your HR dept. files to know how the management-union relation has evolved in your company?
Do you have a single union or multiple unions?
Is it a registered union?
Is it a recognized union?
How long has it been in existence in your company?
Has your management signed any agreements with the union so far? How many? Are they related to wages/bonuses only, or do something else like productivity agreements also form part of it?
What is the policy of your top management towards interactions with the union in matters other than wage or bonus agreements? Do they expect an open-door policy from HR so that the union people can barge in anytime they want and talk to your GM or to you? Or, is it a structured system where they need to raise the grievance as per the procedure, and you react after considering all the aspects involved?
I will certainly share with you some ideas about managing the union.
But, it would not be appropriate to give you a solution without knowing your company's union background. The mechanisms vary depending on various aspects involved.
Hope you understand.
Govardhan