As I mentioned is a comment to this question, I was about to suggest that the vsdbcmd tag be made a synonym of the database-project tag. I also submitted a possible tag-wiki for database-project, which lead me to this question:
I'm not sure that "database-project" is specific enough, given that there are at least two different things that Visual Studio alone has called a "Database project", plus several other related project types (SQL Server project, Data Access Project, and the new SQL Server Data Tools project). All of these could reasonably be called "database projects", but so far the tag itself is being used specifically for Visual Studio 2008 GDR/2010 database projects.
Is there benefit in having separate tags for each of these project types? SSDT projects, in particular, will be "replacing" database projects fairly soon; should we add [ssdt] and [sql-server-data-tools] as synonyms, or let them be their own tags?
And that doesn't include the possibility that other development environments besides Visual Studio could have something one would call a "database project" that would get this tag, which would likely attract the wrong type of followers.