Yikes; this has become messy.
So my Iberia account had 90k in Avios go in, and 6k in Avios from Groupon. I made a redemption for 90k, and transferred the remaining 6k avios out to BA.
It seems to make the redemption Iberia took 84k in points from the bonus avios promo and 6k from the Groupon pile. Therefore I only redeemed "84k of the promo avios".
The call centre were pretty damn rude stating; "I should have read the rules" and hung up. These Avios were clearly treated as a separate balance which is a shame as when I made the redemption there was no clear way to make sure it was these Avios there used!