The law simply refers to "10 minutes playing time", and the extra was certainly playing time.
Not convinced, OB. I don't remember seeing the clock stopped after the 80 mins and there was a lot of mucking about that you would have expected to have seen the clock stopped for during the 80. For example I would not have expected the clock to keep running whilst WB had to go to half way to talk to the no4 to find out if the Wales 3 had been injured or not and was thus required to return to the field. Seems bizarre that his warming up pushes against a fellow player were whilst the YC clock continued to count down.
I thought WB handled that aspect of the match well (clock aside) and kept his cool. I think I would have been very cross with the antics.