Can I configure multiple BT110 devices using one Amazon account?

Yes, you can.  This can be an efficient way for system integrators or IT managers to set up and manage a group of BT110 devices for shared use in offices or hotels where the BT110 devices are managed not by individual users but by a small number of IT or device managers (e.g., not managed by hotel guests but by hotel IT managers or system integrators who service the hotel). 

Please note that, when a group of BT110 devices are registered with the same Amazon Alexa account, some Alexa Communication features such as Announcement naturally apply to the entire group of BT110 devices.  This can be desirable (send announcements to all BT110 devices).  On the other hand, if these features are undesirable for your particular application, then, you will need to disable these features (maybe explicitly).  Additionally, when a group of BT110 devices share the same Amazon Alexa account, they share the same Alexa Contacts.  Therefore, when using voice commands to call by names, the common Alexa Contacts will be used to identify the names for the call.