Does she have a valid residency/Work visa in Bahrain?. Then she will be able to get visa on arraival.
Otherwise, According to your profession and salary per month(Atleast 2000 pm) you can apply for a family visit visa for your wife.

Procedure is very simple.
You should have Marriage Certificate Attested Copy + A No objection letter from your sponsor + Your ID CardCopy + Your Passport Copies + Your Labour Agreement Copy + your wife's PP copy.

Fill an application Form(Available at any typing center) Directly go to Emmigration and submit. Next day itself u will get visa for your wife. It's a Six Month visa. Initially you have to Pay 200 + 20 Visa charge for the First Month. If she plans to stay long, she has to take Medical and you can renew her visa for next five months.

Best of Luck