Dear Hilary,
Thank you for your query on Dipogon-lignosus and good job for spotting the weed! It also goes by other names like okie bean or Cape sweet pea or Mile-a-minute vine. It is a weed that likes climbing up fences and walls. If more of it comes over your neighbour’s fence, it will be tricky to remove as it becomes woody as it matures. I would suggest cutting off green material as it appears on your side of the fence to stop it invading your garden.
The good thing is that it is NOT a State prohibited weed so you don’t need to report it. But it would be great if you can look out for any other strange weeds, some of which look quite pretty but are actually really nasty!  Here’s a link to check out our A-Z of weeds from Agriculture Victoria.