Thanks for the info.
Unfortunately it's the usual "except for these destinations" and "not from all websites" and, although not specifically stated, you would have to buy the rail ticket
at the same time by the look of it. So it is useless to people who already have AP tickets.
If it was £1 always, I'd use it. But for
£3 normally the cheeky sods can bugger off and I will get there under my own propulsion in less time than a bus, at any time I want, and for a shorter journey time than the bus, and with no waiting at bus stops.
Perhaps it should be re-named ChingBus or CostlyBus to reflect the extortionate price?
The last time I was offered PlusBus I was offered a £3 ticket when I was only going one way on that day. PlusBus is £3 for my area per day, yet a single on the bus costs less than that. A return is, last time I got one, the same price I believe. So unless I want to travel all day by bus and not get a train, it's utterly pointless. PlusBus is a shambles.

Which is a shame as it had the potential to be good if it was marketed, priced and implemented properly and sensibly. But it isn't, and this promo isn't going to change that.