Could Germany still build a navy large enough to challenge the Royal Navy after this alternate peace?
Short answerNo. A peace dictated by the victorious Royal Navy would impose especially severe restrictions on German naval industry.
NotesA Germany defeated by British sea power would not be permitted to resume the prewar naval race. If the Royal Navy dictated the peace, it would target German naval industry more aggressively than the historical Treaty of Versailles did. The settlement need not be harsher in every other respect, but its naval restrictions would be especially severe. Germany would therefore lack the industrial freedom to rebuild a fleet capable of challenging the Royal Navy in the near term.