This is an interresting discussion, and one I've though a bit about. Can you use "Suggestion" to make someone a willing target for your next spell? If I have a prisoner, can I tell him "be willing to be teleported back to my prison, or I'll kill you!"? Of course he can refuse, but can he also choose to be willing?
I'd say yes on the latter, I think. But the first, I guess it depends on the effect of the spell being cast. If it leads to more or less certain death, then probably not. But how about teleporting someone to a prison, or to a ship sailing away from the continent? Suggestion can not make the target do something "completely alien" to him. I think this should apply to what the teleport spell is trying to do, too. If it's "completely alien", he'd not be a willing target, otherwise, he could be "suggested" into being a willing target.