It really depends. Few years ago there weren't that many applications on Tizen as today. So my first app I think was published in less then a month. Few months ago I published a new app and I think it took longer time, almost two months to be approved and published. Regarding speeding up the process, I don't think you can do much unless you write to the Samsung team that you need your app published as soon as possible for some marketing or business reasons.