Here's what Mike Andrews posted on over at SoxProspects:
Top Ten Rounds (entire amount counts towards bonus cap)
Round, Overall Pick, Player, Projected Bonus
1 Marcelo Mayer $7,000,000
2 Jud Fabian $2,000,000
3 Tyler McDonough $831,100 (slot)
4 Elmer Rodriguez $300,000
5 Nathan Hickey $410,100 (slot)
6 Daniel McElveny $250,000
7 Wyatt Olds $150,000
8 Hunter Dobbins $150,000
9 Tyler Miller $150,000
10 Matt Litwicki $150,000
After 10th round, above $125K (first $125,000 does not count towards bonus cap)
11 Niko Kavadas $400,000 ($275k towards cap)
13 Zach Ehrhard $150,000 ($25k over cap)
After 10th round, possible $125,000 or less signs (count $0 towards cap)
12 Christopher Troye
14 Jacob Webb
18 Phillip Sikes
Total spent towards cap using these projections: $11,691,200
Red Sox Cap: $11,359,600
Red Sox Cap +5%: (no draft pick penalty): $11,927,580
Super wicked early projected not to sign
Vela, Guerrero, Uberstine, and Hood could all sign if there is roster space. Green appears unlikely.
15 Payton Green
16 BJ Vela
17 Luis Guerrero
19 Tyler Uberstine
20 Josh Hood
There is no chance that Green signs.
I'm guessing that they sign 17 guys and Niko takes less money than Mike projects here.