The Admin allows you to block the phone number but not the email address to non registered users??

Admin Panel allows the phone number to be partially blocked from non registered users with this string

<label>
      <input type="checkbox" <?php echo ( osc_reg_user_can_see_phone() ? 'checked="checked"' : '' ); ?> name="osc_reg_user_can_see_phone" value="1" />
        <?php _e('Only allow registered users to see contact phone number'); ?>
</label>
 
located in  Oclass/oc-admin/themes/omega/items/settings.php

Can we block the email as well by adding a line of code somewhere?

I think osc_reg_user_can_see_phone was created from osc_reg_user_can_see_email, did you checked?