Can a blued Contender barrel be married with a stainless Contender frame?

Yes.

or vice versa

The one caveat is some of the really old blued barrels with the single locking lug will lock up on a ss frame, but you can't open them. So you have to replace the locking lug on the old barrel with a new two piece from t/c. They'll send (or used to) new bold free.

It's not a huge deal if you put the older barrel in the newer frame and it' won't open. You just drift out the hinge pin and disasemble.