I am starting a company that will operate a range of niche travel experiences. Are there benefits of using multiple brands for different experiences?

Only the super big guys can handle multiple brands! And they have separate operations teams handling each one. Humans need to be fully immersed in a brand to do it right, and few can handle many on the same day. Plus how do you cross promote? Doesn't matter if it is online or offline. Notice Amazon is one brand for all they do.

Building one brand is difficult and expensive enough. Start by focussing on the easiest niche, and worry about the rest in the future.

I would suggest you focus on one brand initially but make it flexible. Once you have established a brand you could look at either extending it or diversifying into segments. Suggest that you look at developing a "Unique Travel Experience" banner that can be used for a variety of your niches but I would start with the one you are most familiar and experienced. Let your customers drive your expansion.

I'm more or less in agreement with the previous comments. Starting off with multiple brands in parallel would increase your work load while fracturing your audience. We do see companies operating a hierarchical brand structure -- i.e. many individual brands beneath an overarching company brand umbrella. However, that's usually the result of acquisitions, mergers, spinoffs, and new launches over time. In most cases it's unwise to aim for that initially.

Better to find a brand identity that showcases the full diversity of your travel offerings.

Keep in mind that one brand can branch out in multiple marketing directions. One brand can be discovered in many different ways and places -- each appropriate to the business component in question.

I recommend creating a masterbrand under which you would set up individual profit centres, one per type of travel experience. This allows you to optimally leverage your investment in online/offline marketing AND your operations costs while allowing you to see which of the travel experiences perform most profitably and which are most popular with your target audience (you can expect these may not be the same).

Your tagline/brand promise should cross all product lines. For example, you could use something like "Travel experiences as unique as you are." (After all, it's all about the customer, not you/your products.) Then work all your marketing communications so that your masterbrand becomes known for this benefit and tie individual product positioning to making good on this promise.

Your idea sounds very interesting and I wish you great success with it!