modules/Buy_Together/buy_together_calculation.php
Change this (near line 27):
$_discount = func_bt_get_product_discount($v, 'untaxed');
to this:
$_discount = func_bt_get_product_discount($v, 'taxed');
Open the skin1/modules/Buy_Together/buy_together_added.tpl and change this code. It is found two places in the file, near line 57 & 130, you will want to change both.
{include file="modules/Buy_Together/buy_together_buttons.tpl" button_title=$lng.lbl_...
Run this SQL query in the Patch/Upgrade section
TRUNCATE TABLE xcart_buy_together_products;
