onlineleben - 6:39 am on May 27, 2010 (gmt 0)

I wouldn't worry too much about relevancy. keep it in the broader niche and you keep everyone happy (visitors and SE).
For the ticket site I would recommend to create a booking widget that other sites, preferably hotel sites, can install.
Hotel sites can prepopulate the above mentioned widget with their city name and if possible even with a city name of the visitor (geo targeting). By this the visitor who looks for a hotel room also can find a very relevant page about traveling to that city.
An other advantage: you only have to maintain one page with the widget and have not toplaster 100s of links on your site like 'Flights to Toronto from Rome' or 'Flights to Toronto from Madrid'

Keep it relevant for the visitor!