Well..this is an interesting question...
I needed to know the same thing and even called the LGW arrivals lounge to find out, and I was told no. However, I called international res and was told the following:

Passengers on a PAID ticket: Choice of chauffer driven car service, speedlink, or round trip Gatwick Express transfer.

Passengers on an AWARD--straight mileage ticket: Gatwick Express transfer.

Passengers on an UPGRADED ticket--using a voucher: NADA!

The agent advised me to have the arrivals lounge look under:
Focus Page VFRNAI
F/Display F*VFRNAI

I am emailing consumer affairs to get a TOTALLY CORRECT answer to this mystery and will let you know.