Baseball America has the following players listed as signed by the Red Sox
Eduardo Lopez OF Dominican Republic(#20 prospect)
Eduardo Vaughan OF Panama
Claudia Ochoa RHP Venezuela
Naysbel Marcano C Venezuela
Elio Prado OF Venezuela
Carlos Reyes RHP Dominican Republic
Bryan Gonzalez OF Dominican Republic($500,000 signing bonus)
The Yankees and Cubs both have signed 4 of the top 50 while the Diamondbacks, Phillies, Indians, Giants each signed 3.
Here is the signing tracker from BA.
https://www.baseballamerica.com/stories/2018-mlb-international-signings-tracker/
Eduardo Lopez OF Dominican Republic(#20 prospect)
Eduardo Vaughan OF Panama
Claudia Ochoa RHP Venezuela
Naysbel Marcano C Venezuela
Elio Prado OF Venezuela
Carlos Reyes RHP Dominican Republic
Bryan Gonzalez OF Dominican Republic($500,000 signing bonus)
The Yankees and Cubs both have signed 4 of the top 50 while the Diamondbacks, Phillies, Indians, Giants each signed 3.
Here is the signing tracker from BA.
https://www.baseballamerica.com/stories/2018-mlb-international-signings-tracker/