Reversing the order of the quotes, but bear with me...
Any suggestions or are there any place in or around NYC that you would recommend for a married blond woman in her 30s to meet a younger guy?
It's NYC. There's a zillion places. But, it's not the place that matters here.
Do you know of another way (other than online) for my wife to meet a relatively young (in his 20's) boyfriend who would be cool with her having a husband? She likes fit, young guys (what woman doesn't right?) and she feels creepy going to college bars.
Trying to find "a" guy is easy. Your wife will have no problems doing that. If what she wants is a torrid love affair that lasts a few weeks and burns out in a bursting glory of sexual lust, you should have no problem. A relatively young, attractive woman will have no problems finding that. Wear the right clothes, makeup, shoes, in the right setting, and it's flies to a flame. Her having a husband is a non-factor in this equation.
The question is, what does she want? Does she want more than a lover, a true boyfriend who actually cares about her in more than a sexual way? The average young 20 something guy isn't prepared for being the boyfriend of a woman who has a husband. I don't mean to stereotype, but their emotional maturity is not just sufficient yet to wrap their brains around that concept.
I've seen many, many stories of women who have found a guy to play around with, only to find the guy falls in love with her and wants to steal her away from her husband. Far, far better to find a guy who already knows what the deal is, that stealing her away from you isn't an option. That's why online is so frequently better. Use an online dating service that caters to polyamory. Guys who are on such sites will already know up front what the deal is, and will largely be there because they accept that deal, even before meeting your wife.
My wife and I once met with a guy nearly 20 years her junior. We'd found him via such an online resource. So, one issue out of the way. He was very much attracted to older women, and was quite happy with me being in the picture. In fact, it was good for him as what he wanted wasn't marriage, but a long term relationship where the commitment level was not as thorough as marriage or the prospects of it. He was a college student, and surprisingly mature for his age. We'd agreed to meet with him only because our interactions with him had shown him to be mature. But, this is rare. Few men in their early 20s are at a stage in their emotional lives where they can fit into this picture. My wife almost agreed to date him, but in the end she decided it wasn't for her, despite knowing he would likely be a powerful lover able to go for hours.
I guess it all boils down to what your wife really wants. If a young college age student is really what she wants, then figure out if you're comfortable with a guy who likely isn't going to understand where the borders are. Be cautious.