Currently I don't think that anyone of them is closer or more far away from establishing his place into the first team, I think with time they both will. So my answer to your question includes both of them.
And as about them, it's obvious that Thiago will the be guy with the magic and the skills, while Jonathan will be the team player, doing more of the hard work. (although in Barca everyone should be a team player, but you know what I mean)
They're different, but their characteristics complete each other.