get_the_term_list in a loop

I have a loop that queries a post type to extract the category name and set the class of a list item to that name plus adding a class of “all” as well.
I want to change this so I can use a custom post type & taxinomy instead.
The following code works on a standard post:

<li class="<?php foreach((get_the_category()) as $category ) { echo $category->cat_name . ' ' . ' all'; } ?>">


I’ve tried:

<li class="<?php foreach(get_the_term_list( $post->ID, 'service', 'all')); ?>">


but this breaks