Did about 8-9 surveys a week or so ago...about 4/5 surveys credited to my Avios account using a first Reward for Thoughts account, and the other 4/5 surveys on a different Reward for Thoughts account which credited to my BA Executive Club account.
The avios in each case took around five to six days from completion of the surveys to post on my Avios/BA account.
Hope that helps!