No.
First, union dues are not deductible in 2018. There was a bill introduced to reinstate this deduction, but it never passed in Congress.
Second, they are itemized deductions. If you are taking the standard deduction, $12,000 for single filer and $24,000 for married filers, it will not make a difference on your tax return.
Finally, even if you are itemizing, the amount of the increase in refund would be minimal and likely be less than the cost of filing an amended return.
