I didn't get Avios or TP for my recent OnBusiness redemptions, even though they all went into revenue fare buckets. The
T&Cs are very clear anyway:
14.2 Reward flights are not eligible for Avios or Executive Club Tier Points. Where a Reward Flight Upgrade is made, the member may accrue Avios and Executive Club Tier Points on the part of the ticket that has been paid for.
That said, there have been anecdotal reports of "accidentally" getting Avios and/or TPs (see layz's post above). But as with e.g. points earned for POUGed reward flights, these are the exception rather than the norm.