is there any monthly subscription for bus and train?

Indeed, NS Flex subscriptions are only valid for travel by train. There is no nationwide subscription for unlimited travel during off-peak hours for bus, tram and metro (BTM). BTM subscriptions are usually valid only in a specific region.

If you can specify at what times and in what region you would be travelling, we can give you some advice.

There is a nationwide subscription to get discount on all travel, not just off-peak hours. 

Sadly not, because it would be very useful.

Thanks Tochjo, you are very kind ¡

I am actually in nord brabant (fijnaart), i would like to connect bus from my area till roosendal or breda in this way i cant take the trains to reach Rotterdam , Amsterdam, Den haag etc..

Thanks Tochjo, can I know if i can load this subscription on my ov chipkaart  at the same time than NS Flex?

In theory yes, in practice this combo very often gives probs. Its more prudent to have them on 2 cards. YOu can get a FREE card (not pay 7,50) if you also start right away a NS-subscription on it-but then you have agin to wait 7 days till card is ready.

It makes no sense to ask for ALL transit if you only plan to use lines in a certtain area. And be more dutch: try biking, BraVo is not the finest of connctions into such a faraway little village.

Brabant Dalkorting subscription is probably cheaper or more useful. For 14 or 15 euros a year you get 40% discount on all bus travel in Brabant after 9 a.m. and on Saturdays, Sundays and holiday you get the discount all day ( however in Fijnaart there is no bus service on Sun/Holiday). Maybe on those days bike to Zevenbergen or Oudenbosch trainstation? It isn't that far and you can take the train from there to Dordrecht. And change there for Rotterdam and further afield.

Yeah thanks, already biking but i am doing my math, cos i like to visit big cities to buy food at arab food markets, also fijnaart is a bit faraway from breda or roosendaal and 2h 30m riding a bike daily is not a nice plan for me in winter.

Thanks to all