Well, Charles and Ray designed many things together, but Charles was a prominent designer in his own right before they got married. I don't know if the lounge chair was his or their design.
All the moulded plywood stuff was started and their joint venture during the war...long after they were married (how cool is it to have your wedding ring made by Harry Bertoia).
Previous to their marriage, he was a traditional modernist influenced by Mies, Gropius, Corbusier. They first started working together on the MOMA project in 1940, along with Bertoia and Saarinen. She was the painter/sculptor type. It was only after they married that they became the bohemian types...so maybe she was actually the main driving force behind their scultural style?