Torque Specs for Bicycles?

I am going to raise the handlebars on my wife’s Trek 7000 cruiser bike. (It was purchased in 2009 if that matters). It’s a threaded quill style. What is the proper torque spec for the bolt once I raise it? The bolt uses a 6mm Allan.

How do I find specs for other bolts? Is there a chart somewhere? I wrench on cars and the torque specs are easily obtainable. Bike stuff seems to be a little harder to come by.

Thanks!