Well, in terms of lounge access one never gets it on economy fares, unless one is a SkyTeam Elite Plus (CO Plat) flying on a SkyTeam carrier. VS doesn't qualify.

I don't think the number of CO elites has much bearing on services, particularly lounge access. CO could certainly arrange lounge access for you, but they'd have to pay a set, negotiated fee for each traveler admitted to the lounge. Given how great the LHR Clubhouse is supposed to be, I can assure you that it wouldn't be cheap for CO, and hence they don't offer it. As for access to another lounge, well, write to CO with the suggestion, but I doubt they'll do anything about it...