Hi nes49,
When you import an event from Eventbrite it will also import the assigned venue.
Though this may be similar and even near-identical to an existing venue you manually crafted within your WordPress site, unless it shares the same unique Eventbrite venue ID it will be treated as a separate entity.
It might be possible for us to introduce new logic that looks for address-based matches and if you think that would meet your needs you are more than welcome to propose it over on our UserVoice page:
tribe.uservoice.com
This will also allow others to comment on and support the idea – giving us a great sense for how much demand their might be (by the same token, please do search for suitable existing requests – if you can find one, it would be better to up-vote it rather than creating a separate suggestion).
Thanks!