You can say either, as in that section it doesn't offer specific phraseology, its open to interpretation by each controller. You'd be scared by actually how many of our regs are like that....
The Pilot / Controller Glossary defines "Wake Turbulence" and "Jet Blast." You can use "Wake Turbulence" instead of "Jet Blast" but not the other way around. The reg you post doesn't seem to be a communication reg anyway, it's telling you something to avoid, not detailing how and when to inform the aircraft.

I also assume that you have a "Pilot / Controller Glossary" whouch would be identical in definitions to ours, and I would further assume it's what you're supposed to use for phraseology... 'cause otherwise the whole point of the thing is moot.
However... right or wrong, if you tell me "caution wake turbulence" for an airplane that is sitting there idling on the ground... I'm probobly going to laugh.
