Add a fee to WooCommerce per product, based on category and add to sales tax

I have seen several posts relating to adding a service fee to a WooCommerce item based on Category. Tickets in my case. I have had success with several of the codes presented. However In all cases Sales Tax was not applied to the new sub total. I’m stuck trying to make that happen. So with the code below I am not taxing the up charge resulting in under collection of taxes.
Here is the code I’m currently using:

/* Service fee for tickets */

function df_add_ticket_surcharge( $cart_object ) {

global $woocommerce;
$specialfeecat = 23; // category id for the special fee
$spfee = 0.00; // initialize special fee
$spfeeperprod = 0.214; //special fee per product

foreach ( $cart_object->cart_contents as $key => $value ) {

    $proid = $value['product_id']; //get the product id from cart
    $quantiy = $value['quantity']; //get quantity from cart
    $itmprice = $value['data']->price; //get product price

    $terms = get_the_terms( $proid, 'product_cat' ); //get taxonamy of the prducts
    if ( $terms && ! is_wp_error( $terms ) ) :
        foreach ( $terms as $term ) {
            $catid = $term->term_id;
            if($specialfeecat == $catid ) {
                $spfee = $spfee + $itmprice * $quantiy * $spfeeperprod;
            }
        }
    endif;  
}

if($spfee > 0 ) {

    $woocommerce->cart->add_fee( 'Service Fee', $spfee, true, $taxable = true, $tax_class = 'standard' );
}