I have noticed recently when checking the oil level, that around the oil cap there is a slight bit of oil, I have wiped this clean 2 times now but it keeps coming back could the cap be at fault, or is it just oil vapor escaping

I have used 3/4s of a liter of oil to top up in 7k and the cars done 71k now

Might be worth tightening it a little.

Does it have a rubber seal on cap?

Does it have a rubber seal on cap?

No, all it has is the lugs that fit the top cover

I'd speak to the dealers about getting a new oil filler cap.

When you get a chance next give it a good clean all over and wipe down the section it goes into just to make sure there isn't any debris causing a bad seal.