Thanks John, I ended up solving it, my working code ended up being:
<?php $accommodation_relationship = get_field( 'accommodation_relationship' ); ?>
<?php if ( $accommodation_relationship ): ?>
<?php foreach ( $accommodation_relationship as $post ): ?>
<?php setup_postdata ( $post ); ?>
<?php
if( have_rows('acommodation_location_repeater') ):
while ( have_rows('acommodation_location_repeater') ) : the_row();
?>
<div class="col-md-3 accommodation">
<h3><?php the_sub_field( 'accommodation_name' ); ?></h3>
<p class="description"><?php the_sub_field( 'accommodation_description' ); ?></p>
<p class="address"><?php the_sub_field( 'accommodation_address' ); ?></p><br />
<a href="tel:<?php the_sub_field( 'accommodation_phone' ); ?>" class="contact-link"><?php the_sub_field( 'accommodation_phone' ); ?></a><br />
<a href="mailto:<?php the_sub_field( 'accommodation_email' ); ?>" class="contact-link"><?php the_sub_field( 'accommodation_email' ); ?></a>
<?php $accommodation_website = get_sub_field( 'accommodation_website' ); ?>
<?php if ( $accommodation_website ) { ?>
<br />
<button class="accommodation-bttn"><a href="<?php echo $accommodation_website; ?>">Website <i class="fas fa-chevron-right"></i></a></button>
<?php } ?>
</div>
<?php endwhile; else : endif; ?>
<?php wp_reset_query(); ?>
<?php endforeach; ?>
<?php wp_reset_postdata(); ?>
<?php endif; ?>
Thanks!