Is this plant ready to go into a larger pot?

You can transplant whenever you desire. I myself let it get a tad bigger before I transplant but if you feel ready, then shoot for the stars. Or in this case a pile of dirt...

J Evergreen

 

General rule of thumb for transplanting is if the leaves are past the rim of the current pot, you should transplant. I never transplant. I put the seed in the final pot and let her rip. It's just my way of doing things.