Ok, here is what I found, a little strange:
firebase list shows all firebase projects that you have access to, but they are not yet available (i.e. added as an alias to your current folder project).
CLI firebase-tools firebase deploy --project myproject1, myproject1, .firebaserc = > , .
, , 2 :
firebase use --add ( )firebase use myproject1
= > , firebase deploy --project myproject1 ( --only functions )