metaphorically, yes you could say to harvest the fruit, but it is not the same as 'take the lion's share' which means to take more than other people.
It usually means that if you put in a lot of effort or resources, you will be rewarded by a good result. A company that puts a lot of effort and money into marketing will reap the rewards by winning more customers. A student who studies hard will reap the rewards of good qualifications.