VG bond funds are fine.
Better than fine due to the low expense ratio.
By the way... Sorry for putting my opinion out there... I have no way of knowing your strategy. I am sure it is sound and well reasoned.
But, I would like to express my thoughts on the matter of bonds in a portfolio with years left before intended harvest.
At times, I have somewhat blindly followed the consensus advice without fully understanding why I might go that route... other than smart people say I should diversify into bonds.
IMHO... If I had 25+ years before I intended to use the money, I would keep the majority of my portfolio in equity index funds diversified across countries and capitalization. Keeping some money in bonds is reasonable. keeping some cash in a Money Market makes sense for emergencies (6 months living expenses).
I would probably only put 10-15% in Bonds with 25 years to go. The only reason I would hold any bonds would be in case an unexpected event changed our plans and we needed money right away. The lower correlation between bonds and equity increases your chances that if the unexpected event occurred in a down market, we have some assets that we can sell without damaging our portfolio. By the way, this is where slice dice is superior to an all in one fund approach.
In other words... with 25 years to go, I would view the bonds as a hedge against an unexpected life event. The majority of the holdings would be (in a rational way) pedal to the metal for growth... which probably should include some value stocks.
I am sure the rest of the smart folks on this board are probably saying Duh!
Just want to share an insight.
We did not use bonds early on. With two incomes in two different Industries, DW and I did not feel we would
not need to tap into the money... We could easily make it on one pay check. We have been 100% equity up till a month ago. (except for cash emergency fund). And possibily, we have benefited from luck since we did not have a catastrophic event that required money to be taken form the portfolio. But we have a LBYM lifestyle and do not put ourselves in situations with large finanacial overhang that would cause us to need the money. We decided to diversify into bond now because we are preparing to ER in about 4 years. We had flexibility to delay ER, so the Bond move was not viewed as a neccessity till this late stage. Stated differently, if the stock market tanked and we had to delay ER, we would not have a problem. I am not chomping at the bit to quit work (although, DW is ready). The move into bonds now is to hedge against delaying ER. There are other ways to hedge... but getting fancy has alway caused me to lose money.