On being summoned and asked, Bates does mention, with regret that almost sounds genuine, that hotel policies prevent his being given tattoos by guests; but he would be greatly honoured by the design done in metal or glass.
The design itself is indeed intricate, and large. Spot can etch it into glass well enough - he has al the necessary tools - but it's slow, careful work to copy it from Wilshire's back, and takes a substantial portion of the night (during most of which time Wilshire sleeps).
By morning, Spot has a neatly etched copy of Bates' new badge of rank on glass; the minibar is almost empty; and an SMS from The Man has arrived on Spot's cellphone.
The Man wrote:Have located Radcliffe. Most likely he will attempt to create new Singularity. Ship will be waiting for you at spaceport, with new potential teammate; Steve Roswell. Booking reference number 583835. Details en route.