Menu not showing while using filter hook for custom posts

I am developing a coupon website (http://ift.tt/1Dqez3o). I have a custom post type named offer and each event has a meta value named offer_end_date.

offer post type has two custom taxonomy offer_category and offer_store.

On the homepage I'm trying to show a section named latest section where latest 6 offers will be shown.

I have two different files to display the events for both the taxonomies (i.e. taxonomy-offer_category.php and taxonomy-offer_store.php)

In all these pages (including search result page), I want to show only today's offers and upcoming offers. So I added a filter hook.

function rel_exclude_expired_offers($query) {
    if( $query->get( 'post_type' ) == 'offer' || is_tax() || is_search() )
    {
        $meta_query = array(
            array(
                'key'     => 'offer_end_date',
                'value'   => mktime(0, 0, 0, date("n"), date("j"), date("Y")),
                'compare' => '>='
            )
        );
        $query->set( 'meta_query', $meta_query );
    }
}       
add_filter('pre_get_posts', 'rel_exclude_expired_offers');

The code is working fine, but in category, location (taxonomy pages) and search pages menu is not showing.

If I remove || is_tax() || is_search() from $query->get( 'post_type' ) == 'offer' || is_tax() || is_search(), menu shows properly, but the filter does not work in taxonomy and search pages.

Where's my mistake?