Not sure what I can add to this, but you did kind of answer your own question by saying that you benefit by working under the companies umbrella brand. If that market presence wasn't there through reputation etc, would you be pulling in the business?
It sounds like things are operating exactly like any other business does, and at least you own equity in the business - thats the surly the payout and beneficial situation if the company becomes super successful. If you personally haven't invested any finances in the company and you are at least getting paid work, it's perhaps a bit churlish to start assessing the company as a whole in terms of who is being paid what. Anyone can say exactly the same about any company they work for: "we do all the hard graft, and the directors get the lion's share...its not fair" etc etc etc
I think in the spirit/motivation of all startups - apart from the self made fun factor, is that people get involved for the long game and it's the dream of many to eventually float the company and turn that one percent share into a great deal of cash at some point. But like a previous person said, you all presumably had the discussion already about how equity was to be shared out, so I guess you can either be patient and play that long game, secure in the knowledge that you at least have a cool and paid job!....or, start something up on your own and do what they have done, work hard and take the majority share of your income.
As a side note, I almost set up a 'shared space' studio recently, with the intention of renting out desks to other creatives and perhaps ideally form some kind of co operative business. But, the more I considered it, the more I began to asses what was important to me and came to the realisation that it is not the space itself or the environment that creates a brilliant business, its the people and only the people.
What I would be asking yourself, rather than how much money you are making and what you think is fair, is how happy are you and do you love your work and the people you are working with. If the answer is yes you love your job and everyone there, then I'd say you are pretty darn successful already my friend.
Good luck