The tagline occupies the sample region as the logo.

And the logo works in conjunction with the navigation bar.

So in essense, to increase the width of the tagline requires you to increase the width of the logo and decrease the width of the naviation var in the template.

This is how it is performed.

With Super Administrator mode:

Go into template management and select JB Newstream

Select the logo tab which is under the appearance tab which is under the template tab.

Change the Logo Width from 3 to 4 columns

Select the Menu tab which is under the layout tab which is under the template tab.

Change the navagation width from 9 to 8 columns.