Wiggins has been at his north west home with his feet up since the Olympics, so unless journalists go knocking on his door asking about Armstrong then that's probably why he's said nothing on it.
But regarding Spanish cyclists, his hero is Miguel Indurain, not Lance.
Wiggins has never said anything about doping in countries other than the Southern European ones. Ever. Not about Armstrong, not about Landis, not about his olympic teammate Millar, not about anybody. If he has, I'm yet to read about it.
The only thing he's commented is how in Britain there isn't doping because the culture doesn't tolerate it as much as in those other places.