I bought Swindon > South Bermondsey.
That way it's train to Paddington, tube to London or Tower Bridge then train to South Bermondsey. Saves trying to hail a cab in the middle of the road like last time
I could be missing something here, but don't really understand why you would want to go via Tower Bridge. If you're coming through Paddington, the obvious route would be Bakerloo line to Baker Street, Jubilee line to London Bridge and then overground to South Bermondsey. It sounds convoluted, but is actually rather quick (depending on how many beers you drink en route).