Q: iWatch speaker and ReSound Linx

I currently own an iphone 6 plus and a iwatch. Also, I wear ReSound LINx hearing aids. They work brilliantly together, however, I am having a problem when I answer an incoming call on my iwatch I seem to be unable to utilize the bluetooth speaker capability on my hearing aids. The calls automatically utilize the speaker on the iwatch and not the ReSound hearing aids. When I answer from the iphone I have no problem. The audio comes through the hearing aids loud and clear. Is there a setting that I may be overlooking?