Hello everyone ! I have received a job offer with 700BD+Car. Is this offer good for a family of 2 ?

How much is the cost of a 1/2 BR Apartment in a decent locality?

Hmmmm, I need more details in order to tell you if it's worth it or not. The salary is a lot more than the average salary a middle class Bahraini receives, so if you take it from this sense, then it's great. But at the end, it all depends on the kind of job you'll be doing, the number of hours (and days), your degree, your aims for working here.
Why do you want to work in Bahrain? Do you want to save money or move to live here with your family?
The answers for all those questions lead to whether the job is worth it or not.

If you're looking for a decent apartment in a decent location, it's going to cost you at least 160BD. Of course, prices vary a whole lot depending on where the apartment is.
I'm talking about totally non-furnished apartments of course. Just concrete and tiles!
If you're looking for a semi-furnished apartment with air-conditioners, etc - then you'll have to pay at least 270 BD.
A furnished aparemtn will cost a lot more of course.

But still, the salary should be suffiencient for two people.

Besides your rent, you'll have to pay for utilities - can't estimate really.
And that'll leave you with the regular daily expeses only.
Petrol is not that expensive in Bahrain - and you don't have to worry about buying a car since it's going to be provided for you.

In conclusion, this salary will give you a decent life in Bahrain. You may even be able to save money if you have good money management skills. But again, it all depends on your aim and what you're looking for exactly.

700 BD = around 1860 $
It depends on where you are from and compare it with the best salary that you got in your country.
The appartment will be between 100 to 200 BD.
Food, bills.....etc will cost you around 200 BD.
Entertainment e.g, resturants, cinema, ...etc will cost you around 50 BD.

So, you expendture = 350 to 450 BD/month = 930-1200 $

You'll save around 350 to 250 BD/month = 930-660 $

At the end, it's really depends on your managment.

It depends on which country you are coming from. I see B.D 700 as a low salary for someone to travel oversees. But if the salary is fine with you, you can manage with it especially that you do not have a big family. Decent 2 bedroom appartments start from B.D 150 and above. I am living in one now, and I pay B.D 280 because it is in a good area (East Riffa), but you can get cheaper apartments. Cost of living in Bahrain is becoming very high, if you give more details of the job, I can help you more. Giving you a car is very essential, because you cannot depend on public transportation over here.