You can set the related pricing context for Line Items using the custom setting, Related Price Scope, available at Setup > Build > Develop > Custom Settings > Config System Properties > Manage. This setting enables you to choose if you want to perform the related pricing calculations over the entire Cart or confine the calculations to a Bundle product only. For example, if the price of an Option product is a percentage of another Option product in the same bundle, consider the following scenarios with Related Price Scope = Cart and Bundle:

• Related Price Scope = Cart, the Option price is based on the price of all the instances of the related product in the Cart, whether it is in the same Bundle or a Standalone or in an another Bundle.
• Related Price Scope = Bundle, the Option price is based on the related product instances within the same Bundle. You must also ensure that the Option products are a part of that bundle.