Is "Pull up and be ready" standard phraseology?
After the fact, I can guess that he meant, "Pull up to the runway hold short line, staying on the taxiway, and be ready for immediate takeoff when cleared".  

But his phrasing was non-standard, and definitely confusing.

I think the proper way to say it would have been, "N12345: Hold Short; You are #1 for departure; be prepared to go without delay."

The key parts being:


"Hold Short" is an unambiguous instruction
Informing you that you are next in line.
Informing you what is expected, using the official term "without delay"


Even that is slightly risky, as the "without delay" could be misinterpreted if the pilot misses the initial "hold short" instruction.

I think the proper responses available to the pilot are one of:


"Holding short.  Ready to go without delay"
"Unable"  (I'm not ready yet, perhaps in part because I don't understand)
"Please Clarify" (You used confusing terms; Spell it out for me like I'm 5)