Share content between 2 drupal websites

Hi all,

We are currently running 2 drupal websites

the first website is a public website (our corporate website)

and the second is used as an intranet website (it has calendar and booking system setup.)

the issue we have now is that we receive online booking thru our website that we would like to send to our intranet site.

Our public website user webform to book people to shows and in return we receive an email with that booking and we enter it manual to our internal booking system.

now, I know that I would probably have to re-do the whole thing without the use of webforms and that's why i am asking on the forum for support.

We also want our form to allow users to booking people more multiple shows based on the city the user is in (if you are in a city you see the shows in that city and you just select which one you want to attend (so this option is not available right now and we need to find a solution for it)

Moreover, the internal intranet website is used in a closed environment so so we do not have access to it from the outside at all (all ports are closed).

I don't know if what I wrote is sufficient..

any ideas on how to approach this would be helpful - modules, examples, tools etc...

thanks in advance