Sorry Colin but I'm not sure I fully understand your point. In your eyes, given what he said about celebrity culture and a joke about Cav, he is not allowed to advertise products as that would make him a hyprocrite? Additionally, is it your place to judge such an individual on perhaps a marginal matter?
Of course he is 'allowed to' advertise products and Cavendish and Pendleton are two examples of riders who have already done it. I think it is pretty laughable that people would go out and buy a product based on a famous sportsperson being paid to say they use it but good luck to them - their careers won't last forever.
If Wiggins did the same thing then the problem I would have is that he has indicated that he doesn't like that kind of thing and said that he wants to stay ordinary and have nothing to do with celebrity. Advertisers do not pay people like you or me to advertise Shampoo or bread.
By definition, saying that you disapprove of something and then going off and doing it yourself is hypocritical. For example - senior male Tories lecturing us on 'family values' while happily romping with their mistresses.
Is it 'my place' to question such matters? Blimey, this is the UK in 2012 not the USSR in 1952! I will question anything I want to question!
Is it 'your place' to question 'my place'? Answer - yes, why not?