Do you still need a marriage if super-sophisticated biotechnology is capable of producing humans by cloning?
Well it depends on what you feel is the reason for marriage. If you feel the reason for getting married is simply to procreate then I guess there'd be no need for it anymore, after all, in my opinion, human clones(if they exist) are essentially the same as normal human beings. They breath in the same oxygen and breath out the same CO2, they bleed like us and sleep like us and as such they are human in every sense of the world.
The thing is that people get married for lots of reasons, and one of those reasons is dedicated companionship. Now it's easy to date a person and say you're commited to the person, but until wedding bells ring then the rest of the world will not really recognise the two parties as more than just a guy and a girl who probably occasionally have sex and spend time together.
Science can do alot of things but it can never really take away the need for companionship and all the cloning machines in the world can't change that. The essence of marriage is to raise a family with a person and even though cloning may be an option, it doesn't take away the importance of marriage.
Marriage means a lot to different people, for some people, marriage could mean the joining of two kingdoms, for others it could mean spending the rest of your life with someone and for others it could just mean procreation. Marriage only becomes obsolete when its importance is reduced to procreation alone and as of now it's much more than that.
I hope this helps.