Please read on this blog post if you want to deploy a BDC model to the desired SharePoint BCS service or if you ever run into issues like below...

"When deploying a BDC model in Visual Studio 2010, some people may see this error message “… There is no default Business Data Connectivity Service Proxy available for the given SPServiceContext…” or similar ones. This probably means the SiteUrl feature property is not appropriately set.

SiteUrl is a SharePoint feature property that determines where a feature will be deployed. When a BCS feature is deployed, SharePoint server will look up a BCS service (if there are more than one BCS service connected to the site, it will select the default one) connected to the appointed SiteUrl. If the SiteUrl property is omitted, it assumes the value of SiteUrl is http://localhost:80. The SharePoint BDC project in VS2010 helps you customize the feature properties like SiteUrl. Let me show you how you can easily manage SiteUrl property here.."