For an institutional fund, they can be different, non-fungible pools of capital. The $15M comes from fund limited partner (LP) commitments as part of the investable capital of the fund (i.e. was earmarked for investments and is not the fund manager's money, in a very real sense), but the $100k might (depending on the LP agreement for the fund) come out of the management fees, and if so, is very much part of the P&L for the fund manager.

For a corporate VC, its typically all the same pool, though.