Records in CRM 2011 that have a Customer lookup, such as Opportunity, have the following relationships.
|Account: Opportunity||Parental||Potential Customer|
|Contact: Opportunity||Parental||Potential Customer|
All field names can be used in views but whether Account (or Contact) is populated depends on how the record was created. If, for example, an opportunity is created from within an account then both Potential Customer and Account will be set the name of the account. However, if an opportunity is not created from within an account, then Account is blank even when the Potential Customer is set.
Furthermore, if the Potential Customer is changed on an opportunity which was created from within an account, it seems that the value of Account is not changed to match the new Potential Customer.
Note: in CRM 2013, Potential Customer is not shown by default.