Jane Pettigrew chats with Bruce Richardson over tea at The Athenaeum.I had the opportunity recently to preview the new Gentleman's Afternoon Tea offered at London's 5-star Hotel Athenaeum, located in fashionable Mayfair on Piccadilly across from Green Park. Afternoon tea unfolds here every day in the sunny Garden Room, enclosed on one side by the hotel’s unique ‘Living Wall’ – home to…