How to remove the Tagline
In order to remove the tagline that appears just below the logo image, please go to Dashboard > Settings > General > delete the Tagline text
How to hide the Tagline
In some cases you'll need to hide the Tagline text below the logo image.
In that case you can hide the tagline using this code:
.fixed-header-box .logo-wrapper .logo-tagline { display: none; }
Here's the guide how to add the Custom code to the Vamtam theme: How to add custom CSS / PHP code or modify the theme code?
You can find some useful tips for your Tagline content here: http://wpcookhouse.com/tagline-seo/