The plan is over the next few years to develop, operate and run a range of unique travel experiences - each which could develop into a sustainable product line on its own. These include: culinary tours / experiences; green / sustainable tours; experience that have a strong focus on social innovation in a country... These can all be operated with the same operations team, but the real question is whether to target niches I am best to create multiple brands each targeting a separate niche, or maybe multiple sub-brands. Or is it best just top create one very strong brand. Obviously running multiple brands is not an easy thing! Will be relying on a combination of online and offline marketing and sales.
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!