You will have to contact the reseller/ sales team. There is no automated way to combine single app plans and full CCfT licenses. The way I understand it it's basically some sort of hack that blacklists the other programs for a given CC activations since there are no proper management options for this in place and this has to be doen manually.
Thanks Mylenium however according to the online chat support, it is not possible to have a single app license and apply it to a team member. The team member needs to sign up with their own email address to use any single app. Seems rediculous, but that I what I have been told.
If anyone knows any different and can explain to me how it can be done or who I need to speak to, then I would love to hear from you.