Is it possible to convert a bulldozer using a Dominator skill

Judging by the perk's description you may only have 1 turned companion to fight for you.

The detail on the Payday 2 skills site, which utilises information scraped from the game files suggests the following:

• With no skills, any player should be able to answer two pagers without issue
• With Smooth Talker, a player with the skill can answer four pagers without issue

If you have a team with a player that has the Smooth Talker ability, the rest of the team is able to answer the first two pagers but the player with Smooth Talker has to answer the rest.

If you have a team with multiple Smooth Talkers, this will still only guarantee that you can answer four pagers, but it gives you more flexibility regarding who in your team can answer.