When BizTalk and SQL Server are on different computers, the BAM configuration may fail with the following error:

A network-related or instance-specific error occurred while establishing a connection to SQL Server. The server was not found or was not accessible. Verify that the instance name is correct and that SQL Server is configured to allow remote connections.
(provider: Named Pipes Provider, error: 40 - Could not open a connection to SQL Server)

 

There is a bug with the BAM configuration when BizTalk and SQL Server are on different computers, as described in the following KB article:

2832137  FIX: BAM tools cannot be configured in a multi-node BizTalk Server 2013 environment

 

This issue if fixed in BizTalk Server 2013 Cumulative Update 1, which is available on Windows Update.