What's the most efficient way to get Level X Gathering Materia?

[Jojoya]

Is that real life or eorzea time?

Those times listed are Eorzea time.

Also keep in mind that was information for spiritbond farming as of 5.3 using Pactmaker gear. If you've already upgraded to Indagator, your spiritbond rate is going to be extremely slow even if using a Spiritbond potion.