Вопрос закрыт.
Для тех, кому интересно привожу код решения.
<div class="row">
<div class="col-lg-12 col-md-12 col-sm-12 col-xs-12 col-xxs-12">
<h1><span><?php single_cat_title('Каталог: '); ?> id=<?php echo $category_id = get_cat_ID();?></span></h1>
<?php $cat = get_term_by('name', single_cat_title('',false), 'company_category'); echo $catSlug = $cat->slug; ?>
</div>
</div>
<div class="row">
<div class="col-lg-9 col-md-9 col-sm-9 col-xs-12 col-xxs-12 ">
<?php
$mypost = array(
'post_type' => 'company',
'posts_per_page' => 15,
'tax_query' => array(
array(
'taxonomy' => 'company_category',
'field' => 'slug',
'terms' => $catSlug
),
),
);
$loop = new WP_Query( $mypost );
?>
<?php while ( $loop->have_posts() ) : $loop->the_post();?>
<article id="post-<?php the_ID(); ?>" <?php post_class(); ?>>
<div id="post-<?php the_ID(); ?>" <?php post_class(); ?>>
<a href="<?php echo get_permalink(); ?>"><?php echo get_the_title( $ID ); ?></a>
</div>
</article>
<?php endwhile; ?>
</div>
</div>
