That's great. Has he indicated how much interaction they have at work currently? Like, do they see one another and interact already?
If not, the bar setup is a great idea. Will she at least recognize her? That opportunity should be used to get them as close and comfortable as possible. As a guy he should be able to take it from there. Once there's been a formal introduction and there is at least a bit of familiarity he can begin expanding on it. Approaching her at work, saying hello, inviting her to lunch, etc. It sounds like he is motivated and wants to fuck her, so there's a great chance things will take their natural course.
I speak from experience in saying that a male co-worker can turn a wife into a slut and you won't be able to stop it. The workplace is an arena you aren't going to be able to interfere with, and she has an ongoing reason to visit. Over time he can easily become friends just through the ****** proximity circumstances, and one thing will lead to another. Day after day she leaves to go to work and will spend time with another man. If that man is actively trying to turn her into a slut, eventually she will give in. You won't be able to stop it - you'll just spend the entire day knowing she's with another man at work and there's nothing you can do about it. Then you'll know she's going into work to suck his cock, and take it deep in her pussy. Then come home to you at the end of the day a used *****. The office is just the perfect conditioning/breeding ground for sluts. They're already dressed to impress, separated from their husbands, surrounded by men in positions of power and authority. It is almost like the entire corporate structure is designed to turn women into slut wives.