Normally, the conclusion of bankruptcy proceedings discharges the debtor from all debt; that’s the very purpose of bankruptcy. In Becker’s case, however, discharge was suspended indefinitely because of the hiding of assets that he was convicted of (link). I’d therefore say that his creditors still have their legal claims against him. The interview fee was, however, paid in Germany, and is now, I suppose, in a bank account in Germany; to seize it, creditors would therefore have to obtain court orders from German courts, and under German law courts have discretion to exempt an amount which they consider necessary for the debtor’s livelihood (I’m a German lawyer, but my knowledge of this area of law is admittedly murky; I suppose, however, that the applicable provision would be this one).
It might of course be that behind the scenes, there is already an agreement between Becker and his creditors on this.