I had a similar problem, and i fixed it look for other bundle tasks comand in deploy log (for example db:migrate) :
sidekiq_cmd_pre = 'cd #{current_path} && ( PATH=/home/deployer/.rvm/bin:$PATH RAILS_ENV=production ~/.rvm/bin/rvm default do'
set :sidekiq_cmd, -> { "#{sidekiq_cmd_pre} bundle exec sidekiq)" }
set :sidekiqctl_cmd, -> { "#{sidekiq_cmd_pre} bundle exec sidekiqctl" }
P.S. not beautiful, but work )
P.P.S need
set :sidekiq_pid, -> { "tmp/pids/sidekiq.pid" }
remove #{current_path}