As you may know, Teamviewer gives each computer that it is installed on a specific number, called the Teamviewer ID. As long as Teamviewer is running on the computer that you wish to connect to, and as long as you know the ID of that same computer, you are able to connect to that computer.
To specifically answer your question, you would need to provide Alice with the Teamviewer ID associated with Bob's computer. If you have Bob's computer on Dave's list in Teamviewer, you can easily discover what the Teamviewer ID is by right-clicking Bob's computer in the list, selecting the gear icon in the upper right hand corner, and clicking Properties. Once Alice has this ID, she will be able to connect to the computer after providing the password that you have set up for Bob's computer (if any) or providing the password that appears on Bob's Teamviewer interface when he starts up Teamviewer.