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'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.