[EE] Nickel plated brass vs Zinc plated steel

Hi,

An M18 inductive proximity sensor that I buy from a reputable brand has a Nickel 
plated brass body, and is (or at least it used to be) supplied with a pair of Nickel 
plated brass mounting nuts.

They have now begun supplying the Nickel plated brass sensor with Zinc plated 
steel mounting nuts. On questioning they quote increases in the price of brass and 
worries about supply as the reasons for the change. Fair enough, possibly.

I am happy with my original choice of nickel plated brass in providing a suitable level 
of corrosion resistance in this application, but I'm less than happy with Zinc coated 
steel. My main question though is, are Nickel/Zinc even galvanically compatible?

Probably other forums to ask on, but hopefully interesting here as well.

Brent