Is it important for my marketing materials to match my website?
Don’t match. Coordinate.
You should find elements of each to play off of when designing one or the other. Printed marketing materials have their own essence of navigation and design. When you plan and design a brochure you start from the front, and lead the viewer through the information by how they open the piece and read through it. So you are able to lay content and imagery based on a static image size.
With a website, your navigation is non-linear. The viewer can look at any page in any order and there is not a fixed size or space. It is important that you design for the viewing habits inherent in each media. “Lead” the viewer with calls to action through and to the information they are looking for clearly and intuitively.
Branding is the important factor here. The viewer that has come from your printed materials to your site should take solace in that they have arrived to the correct site. This is fulfilled through branding each appropriately to their medium. It could be as simple as the color pallet and font usage that is all that ties it together while stylistically being similar.
Don’t simply reconfigure a printed design to fit on a webpage and vice versa.