bmi diamond club - Pre-booking seats on other Star carriers?

I am due to travel from Jo'berg to Munich next week with SAA and the company have booked me in 'Y'. The cost to upgrade to 'J' for that sector is silly, so the next best option is to try and get an emergency exit seat in 'Y'. My question is, as a DC Gold Card holder, can I phone up the DC Gold Card line and pre book my seat on SAA since it is another Star Alliance carrier?

I would have considered using miles to obtain a ticket for that sector in 'J' but it is part of a through journey, so I guess it would just cause complications and the short notice too would probably add a degree of difficulty too!

Any advice or information would be greatly appreciated!

Why would you call DC?

You're flying SAA......so call SAA.

But will SAA give me the time of day when I am not part of their own frequent flyer scheme and I am sitting in steerage?

I had recently travelled MAN-LHR-ORD and the MAN-LHR sector was marketed as a UA codeshare which was operated by bmi. DC prebooked my seats on United LHR-ORD in addition to MAN-LHR (which I was not bothered about!!!) which is why I am asking.

Both DC and SAA will help. DC were more than prepared to allocate my seats at time of booking. SAA were also happy to help change them!

Pick and choose as required! :)

Both DC and SAA will help. DC were more than prepared to allocate my seats at time of booking. SAA were also happy to help change them!

Pick and choose as required! :)

Indeed, but you booked via DC, hence they would help. The OP isn't booking via DC, so they won't be quite so inclined / able to assist in these circumstances. SAA will be the best bet here.

Once one airline sees that the booking has been issued/ticketed by another airline, they usually won't touch it with a 10ft pole

I would also say your best bet is to get in touch with SAA.....I have no idea what their seating policy is though. DC would have helped you out had it been a miles redemption but I don't see it as being anything to do with them otherwise even as a Gold card holder.

My last DC miles redemption involved LH and TG flights - I just phoned LH and TG for seat allocations.

As a general rule, you are usually better off calling the operating carrier to get a seat assignment. Even if the ticketing carrier may assign seats, they sometimes have only a partial access to seat maps whereas the op carrier will have mroe control.
Some airlines can be difficult and ask you to speak to whoever issued your ticket for seat assignments but I am not aware of any *A airline playing such silly games.
Where it does get tricky sometimes with some *A airlines is for codeshares. There are situations where neither the airline under whose code you fly nor the op carrier can assign seats. I have experienced that with a TG-coded, NH-operated flight. This, however, is somewhat unusual. In any event, the OP does not appear to be flying under a codeshare so this is moot point in his/her case.

But will SAA give me the time of day when I am not part of their own frequent flyer scheme and I am sitting in steerage?They will see that you are *A elite and this is what matters as some carriers reserve some seats to elites.