Neither email, from Perfect Venue nor from Bounty Hunter, is ideal. One thing that may help is if the Perfect Venue email makes it into the host's inbox; maybe start the subject line with “Bounty Hunter…” Event or Review requested. If they see the name of the venue where they just had the event, they will be more likely to open the email and leave a review. Right now, the venue name is at the end of the subject line and may not be seen in their preview window.