As an admin you can select a custom hashtag for your network.

Go to Admin -> Networksettings and find the inputfield for 'Twitter hashtag".

Enter a text for the hashtag (with or without #) that will be used as the custom Twitter hashtag for your network.

All the users in the network that have connected their Twitter account to the network, can use the default #wv or #workvoices, and can now also use your custom hashtag to identify whether or not the Tweet should be imported into WorkVoices.