Can you get a removable tow bar if you have an autobiography? I.e. the big rear bumper?

Yes you can. Just got to take the flap off the rear. Be careful with the clips cause they snap. Might be worth getting hold of a few just in case.  MY11 Autobiography supercharged. Santorini Black. Monaco interior. Rear screens. Privacy.
Gone MY08 Supercharged HST. Java black. Ivory premium interior. Rear screens. Privacy. Missed a lot.
Gone MY04 Discovery V8 Petrol ES Premium. Awesome.

Yes, the 'tow eye cover' comes off the same as the standard bumper.
I use a 10p coin to undo the clips, as long as don't use too much force, you should be fine.

If you've not used the tow bar before, worth making sure there's no muck up inside the receiving bit on the car and maybe a couple of squirts of WD40 up there too, as they can start to rust fairly quickly from what I've seen  ON THE WAY: BMW F21 M140i
MERCEDES GL350 - Metallic Navy Blue w/Grey interior

GOING: BMW F31 335D MSport+ xDrive Touring
GONE: Land Rover Discovery 4 HSE - Stornaway Grey w/Black Interior (wish we'd kept it )
GONE: BMW F10 520D MSport - Carbon Black
GONE:MY12 RRS SDV6 HSE Sumatra/Ivory/Grand Black Privacy glass

Cheers. ordered one from my dealer, getting the bike rack fitted. too mucky keep putting it in the back and folding seats down.

Done

Click image to enlarge

Stealthy  ON THE WAY: BMW F21 M140i
MERCEDES GL350 - Metallic Navy Blue w/Grey interior

GOING: BMW F31 335D MSport+ xDrive Touring
GONE: Land Rover Discovery 4 HSE - Stornaway Grey w/Black Interior (wish we'd kept it )
GONE: BMW F10 520D MSport - Carbon Black
GONE:MY12 RRS SDV6 HSE Sumatra/Ivory/Grand Black Privacy glass