How did the planter elite maintain alliances with their smallholder neighbors?

They did this by accepting who they were and where they lived. They had to as many others did not appreciate the colonials. To prevent uprisings like bacon's, chesapeake gentry found ways to assists middling and poor whites by gradually reducing taxes and encouraging them to use slave labor, allowed yeomen/tenants to vote and in turn expected them to elect planters to office and defer their rule, elite used their control over house of burgesses to limit the power of the royal government and hundreds of yeomen farmers benefited by getting a taste of political power and garnering substantial fees and salaries and deputy chiefs, road surveyors, etc.