Gemma was gravitating towards Jonathan in order to get to the Kardashians
 

Think about it--she designs clothing for curvy women.
She was using Jonathan for connections.
She probably is looking to get her business to hop up across the pond as well as for celebrity clientele.

Like that scene when they were sitting around talking about the Kardashians and Gemma is perched on the bed licking her chops.
Even so, even so she let him leave because, as long as she slips her business card into his pocket, it's just one less competitor in the game.

I agree. I think Tiffany tried this initially also but then she dropped it.

Jonathon looked quite awkward on BOTS when the panel told him Gemma wanted him to introduce her to Kim - perhaps he's used to people using him to get to Kim and was disappointed.

I don't think she was using him though - it was just a plus in their friendship.