How to associate posts to users if posts are already associated to another model?

How to associate posts to users if posts are already associated to another
model?

Im on rails 4. Im creating a wine review app and I have three models.
class User < ActiveRecord::Base
has_many :reviews
end
class Wine < ActiveRecord::Base
has_many :reviews
end
class Review < ActiveRecord::Base
belongs_to :user
belongs_to :wine
end
As of now I have my review form like this
<%= form_for [@wine, @review] do |f| %>
...
<% end %>
This associates the new review with the wine being reviewed. How would I
make it so when I create a new review, it associates the current_user with
the review? Thanks.