Your dislike for unions is noted. At most flying jobs, without the ills of the unions, safety would be nearly non existent. Pressure to fly questionable airplanes would be heavy. Seen it, been there. (corporate size/non union commuter/union commuter/cargo). In the military, we didn't need a union, but despite money shortfalls, we did believe in safety and were a non profit so we didn't have to 'go'.
Glad your small outfit works for you and money and safety is of no concern. My company it is a challenge every day. Union crews climb in with non union crews who succumb to most every pressure when their career is on the line. Union keeps my job so I can take care of the customers and deliver their stuff like they really want.
I see a union as much to protect me from a person who would fly unsafe airplanes and become a management pet and thus a Capt, etc ahead of the safety minded pilot. Been there too. All this doesn't mean I don't understand the business end and limitations of unions. However, the OP should simply ask his wife, "Does my safety and job stabilty matter to you?" If she answers yes, then at his current company, a union is probably the better answer. At yours, not so much. BTW, what if the other pilot is your last post was willing to work for half of your current price? Leverage it is, and not for you.