I just learnt from the case of a colleague in a similar situation (there are a lot of us former JK *G looking for a substitutive loyalty program). He basically send a claim for all the flights done with StarAlliance in the last 6 months. He obviously managed to get credit for the StarAlliance flights that he had not credited to his JK card when the company went bankrupt. However, he also managed to get credited for some of the flights he had already credited to JK... flights with Turkish were credited, while the ones with Austrian and Lufthansa were not (or at least had not been yet). Whether this was a mistake or the company's policy, I cannot tell. In any case, it is worth a try.